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Nortel DMS-250 Reference Manual

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297-2521-106
Digital Switching Systems
DMS-250
ISDN Reference Manual
MWC14 (CSP14) Standard 23.01
March 2001

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Summary of Contents for Nortel DMS-250

  • Page 1 297-2521-106 Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14) Standard 23.01 March 2001...
  • Page 3 Information is subject to change without notice. Nortel Networks reserves the right to make changes in design or components as progress in engineering and manufacturing may warrant.
  • Page 5 Standard Release 21.01 for release MCI16 (CSP10). The following information has been added: MAUUI Over Release Message for NCAUUI (AX1408) PRI Connected Number Transport (AX1414) MAUUI In First Call Clearing Message Before Connect (A60006311) Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 7: Table Of Contents

    Line coding 2-6 Network customer terminating equipment and cross-connect point 2-7 Test equipment requirements 2-9 Performance and maintenance 2-10 Performance group alarms 2-10 Carrier group alarms 2-10 Alarms 2-10 Display fields 2-11 Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 8 vi Contents TRAVER enhancements 2-13 Originations on PRA250 trunks 2-13 Datafill trace 2-14 D-channel handler Introduction 3-1 Hardware configuration 3-1 Functionality 3-1 Installation 3-2 Loading the D-channel handler from the MAP terminal 3-3 Returning the D-channel handler to service 3-3 Checking the D-channel handler load name 3-3 Verification 3-3 Running internal continuity tests 3-3...
  • Page 9 Network-initiated normal call clearing 5-25 Disconnection of an EVS call 5-26 Cause and treatment handling 5-29 Standard cause and treatment handling 5-30 Enhanced cause and treatment handling 5-31 Q.931 cause values 5-32 Location codes 5-32 Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 10 viii Contents Mapping of cause values to treatment 5-33 Mapping of treatments to cause values 5-35 Exception conditions 5-37 B-channel glare 5-38 B-channel lockout 5-40 No response to SETUP message 5-42 No response after a CALL PROC message 5-43 Protocol violations 5-43 PRI interworking Agents 6-1 Originators 6-1...
  • Page 11 Fraud Call Interrupt 7-54 Interactions 7-56 Datafill 7-57 Dialable Wideband Service Introduction 8-1 Hardware requirements 8-1 Trunk types 8-2 Translating and routing 8-3 Route selectors 8-3 Constraints 8-4 Protocol datafill 8-4 Signaling 8-5 Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 12 x Contents ISDN SETUP message 8-5 Selecting a route 8-7 Channel selection grouping 8-7 Channel selection sequence 8-8 Channel availability selection 8-9 Datafill for channel selection 8-10 Datafill values 8-11 Potential routing problems 8-11 Fragmentation 8-12 Glare 8-12 Datafill and subscription parameters Parameter groups 9-1 Parameter relationships 9-1 Facility-related interface parameters 9-2...
  • Page 13 Single PRI per DS-1 11-1 Usage of non-PRI channels on DS-1 11-1 D-channel handler to DS-1 mapping 11-1 Recommended D-channel handler to DS-1 mapping on DMS-250 DTCI 11-1 Optimal DS-1/D-channel handler card assignments on DMS-250 DTCI 11-2 Signaling terminals 11-2...
  • Page 14 xii Contents Variable length private dialing 13-18 Direct termination overflow 13-18 Enhanced overflow 13-19 Registered access calls 13-20 Global flexible SAC 13-20 PRISM services 13-21 Universal translation 13-21 Long call disconnect 13-22 Non-standard routing 13-22 Class of service screening 13-22 Test calls/automatic trunk routing 13-22 Trunk group class-of-service screening 13-22 Data calls 13-22...
  • Page 15 Functional overview 19-1 Feature description 19-2 PRI–PRI scenarios 19-3 ISUP-ISUP Scenarios 19-7 PRI-ISUP/ISUP-PRI Interworking Scenarios 19-9 Network Scenarios 19-15 Special Cases 19-17 ETSI PRI 19-21 Billing 19-22 List of terms 20-1 Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 17: About This Document

    (OSI) and ISDN layers. Chapter 2, “DS-1 configurations,” provides an overview of how a DMS-250 switch connects a DS-1 trunk to a single-line PBX; describes the hardware configuration for the DS-1, commissioning details, and performance and maintenance details. Included is an overview of digital trunk controller versions and integrated trunk access.
  • Page 18 xvi About this document Chapter 4, “Message structure and functions,” defines the purpose of each of the mandatory information elements and other information elements of messages; describes messages supported for PRI call processing and their role in call processing. Included are detailed definitions of Q.931 and Q.932 messages’...

  • Page 19: Intended Audience

    DMS-100 Family Guide to Nortel Publications, 297-1001-001. This document is written for all DMS-250 Family offices. More than one version of this document may exist. To determine whether you have the latest version of this document and how documentation for your product is organized, check the release information in DMS-100 Family Guide to Nortel Publications, 297-1001-001.

  • Page 20: References In This Document

    About this document References in this document DMS-250 Master Index of Publications is referred to in this document. DMS-250 Network Control System Reference Manual, NTP 297-2521-138 DMS-100 Trunks Maintenance Guide, NTP 297-1001-595 Integrated Services Digital Network Product Guide, NTP 297-2401-010...

  • Page 21: How Commands, Parameters, And Responses Are Represented

    Subscriber service will be lost if you remove a card from the active unit. How commands, parameters, and responses are represented Commands, parameters, and responses in this document conform to the following conventions. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 22: Input Prompt (>)

    xx About this document Input prompt (>) An input prompt (>) indicates that the information that follows is a command: >BSY Commands and fixed parameters Commands and fixed parameters that are entered at a MAP terminal are shown in uppercase letters: >BSY CTRL Variables Variables are shown in lowercase letters:...

  • Page 23: Introduction

    PRI is transmitted over a DS-1 trunk. The DS-1 is a collection of 24 imbedded DS-0 channels. Each DS-0 can be used as one of the following: PRI B-channel PRI D-channel provisioned channel Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 24: Q.931 Signaling Protocol

    1-2 Introduction Any of the 24 DS-0 channels in a DS-1 trunk can be a D-channel, but convention designates the DS-0 in the 24th position as the D-channel. Q.931 signaling protocol The standardized, all-digital characteristics of PRI support Q.931. PRI combined with Q.931 makes up a common channel signaling system using a protocol that fits into the OSI model.
  • Page 25 Layer 2 controls the flow of data while supervising error recovery and link flow control. Layer 3, Network—Provides services related to moving data through a network. Layer 3 provides and manages logical channel connections between end points of a network. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 26: Isdn Protocol Layers

    1-4 Introduction Layer 4, Transport—Transfers data between sessions transparently. Layer 4 handles communication between the two end systems and enhances, where necessary, the quality of services provided by layer 3. Layer 5, Session—Responsible for administration services, control of data exchange, and delimiting and synchronizing data operation dialogue services.

  • Page 27: Layer 1 (Physical) Protocol

    D-channel, each of which forms a logical link (defined in CCITT recommendations I.440, Q.920, Q.441, and Q.921). There are two types of logical links: — broadcast—used for line (not trunk) implementation of ISDN Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 28: Layer 3 (Network) Protocols

    1-6 Introduction — point-to-point—DMS-250 switches use only point-to-point links Layer 3 (network) protocols Layer 3 (described in CCITT recommendations I.450, Q.920, I.451, and Q.931) provides the means to use the D-channel for establishing, maintaining, and completing calls on a logical link created by the link layer.

  • Page 29: Ds-1 Configuration

    DS-1 configuration This chapter gives an overview of how an MWC DMS-250 switch connects a DS-1 trunk to a single-line private branch exchange (PBX). Introduction The ISDN digital trunk controller (DTCI) is an enhanced version of the existing digital trunk controller (DTC) peripheral interface.
  • Page 30 2-2 DS-1 configuration Figure 2-1 DTCI shelf configuration (front view) 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 * Optional The 25 card slots in the DTCI shelf are split into upper and lower sections. This allows each populated slot to have one online module and one standby module.

  • Page 31: Commissioning

    A pattern is placed in the F-bit to identify the location of the signaling frame. A superframe format (SF) consists of 12 DS-1 frames. Bit error rate (BER) monitoring is accomplished using two indicators: bipolar violation (BPV) and cyclic redundancy check (CRC). Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 32 2-4 DS-1 configuration — BPV is an indication of a coding error in the received bit stream. BPV indicates local span performance. — CRC, applicable only with extended superframe format (ESF), is an indication of one or more bit errors in a block of bits from the received bit stream.

  • Page 33: Channel Ordering Sequence

    CRC is used as an end-to-end bit error rate indicator. Channel ordering sequence The channel ordering sequence is shown in Table 2-3. Table 2-3 Channel ordering sequence Time slot D3/D4/ESF —continued— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 34: Line Coding

    2-6 DS-1 configuration Table 2-3 Channel ordering sequence (continued) Time slot D3/D4/ESF —end— Line coding Line coding for a DS-1 is bipolar alternate mark inversion (AMI)/2B1Q. The 6X50AA DS-1 card supports zero code suppression (ZCS) line coding, and the 6X50AB DS-1 card supports bipolar eight zero substitution (B8ZS) or ZCS, with the following conditions: ZCS coding format requires that the B-channels be used in the 64 kbit/s restricted mode.

  • Page 35: Network Customer Terminating Equipment And Cross-Connect Point

    Network customer terminating equipment (NCTE) is generally located in the central office repeater bay, such as the LD-1 shown in Figure 2-2. Also shown is a DMS-250 switch, customer premises equipment (CPE), and digital signal cross connect-1 (DSX-1) cross-connect point. In the United States, NCTE is part of CPE;...
  • Page 36 Reduce the cabling distance to the LD-1 or DSX-1 by about 27 feet (9.2 m) when measured from the input/output (I/O) filter assembly, PN P0643763, located at the bulkhead (I/O panel) of the DMS-250 switch cabinet. Switch settings for distance Table 2-4 lists the DMS-250 switch settings based on distance.

  • Page 37: Test Equipment Requirements

    DS-1 line simulator A DS-1 line simulator/monitor can be used to verify the integrity of the DS-1 trunks between a DMS-250 switch and a PBX. The line simulator can perform the following tasks: monitor a single path without being part of the primary path...

  • Page 38: Performance And Maintenance

    2-10 DS-1 configuration Performance and maintenance The carrier level of the DMS-250 switch MAP terminal contains alarms and display fields that are indicators of the DS-1 trunk performance. To access the carrier level of the MAP terminal, enter the following command: >MAPCI;MTC;TRKS;CARRIER...

  • Page 39: Display Fields

    When the DS-1 trunk is commanded to enter the local alarm mode, a remote alarm pattern is transmitted. This pattern transmission is delayed for 2.5 0.5 s after the receipt of the message from a DMS-250 switch. When the DS-1 trunk is commanded to exit the local alarm mode, it stops sending the remote alarm pattern.
  • Page 40 2-12 DS-1 configuration errored seconds (ES) severe errored seconds (SES) unavailable seconds (UAS) states Frame slip A frame slip occurs when the transmit clock and receive clock on the DS-1 trunk are not synchronized. When this occurs, a frame must be inserted or deleted.

  • Page 41: Traver Enhancements

    TRAVER is able to follow the path that the translations would follow for PRI on the DMS-250 switch. For more information on the TRAVER command, refer to DMS-250 Commands Reference Manual. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 42: Datafill Trace

    2-14 DS-1 configuration Datafill trace The following shows an example TRAVER call trace. The first three tables TRKGRP—provides the LTID (in this case, ISDN 45) that TRAVER uses to perform further translation of a routed call LTCALLS—(indexed by ISDN 45 and the call type from the command line) provides the appropriate CALLATTR index or RTEREF CALLATTR—(indexed by the CALLATTR field in table LTCALLS—in this case, 4) provides information needed to translate the call...

  • Page 43: D-Channel Handler

    — controls the transmission and reception of high-level data link control (HDLC) frames Functionality The DTCI master processor communicates with the ISP through shared memory. Figure 3-1 illustrates the relationship between the D-channel handler environment and the various ISDN layers. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 44: Installation

    (HDLC) circuitry (resident in the ISP) onto a DS-1 channel. The DS-1 is a 24-channel (64 kbit/s each channel) carrier that provides the medium of communication between the DMS-250 switch and the PBX. The ISP card, located in slot 16 of the DTCI shelf, provides the capability to do ISDN-specific front-end processing for PRI applications.

  • Page 45: Loading The D-Channel Handler From The Map Terminal

    Running the external continuity test The external continuity test checks the end-to-end continuity of the D-channel. The test path runs from the DMS-250 switch DCH to the far-end PBX. The loopback at the far end must be set by commands at the far end.

  • Page 46: Troubleshooting

    Baud rate (field DCHRATE)—datafilled at the local end (in Table TRKSGRP) may not match that at the far end of the DS-1 channel. NETWORK setting—The DMS-250 switch is considered to be the network in the layer 2 protocol. This means that entry IFCLASS in Table TRKSGRP must be set to NETWORK.

  • Page 47: Pri D-Channel Backup

    D-channel and a warm switch of activity (SWACT) capability. In the DMS-250 switch product series, DTCI type XPMs are supported by D-channel backup. The ISDN access controller type XPM is not supported with D-channel backup.

  • Page 48: Map Commands For D-Channel Maintenance

    3-6 D-channel handler format, but only one D-channel (either primary or secondary) can be active in layer 3 at any one time. The other D-channel is active in layer 2. Figure 3-2 shows the basic nonassociated signaling of a PRI interface that contains three DS-1 facilities.

  • Page 49: Message Structure And Function

    An information element may be sent from the user to the network, from the network to the user, or in both directions. Information elements ignored by the DMS-250 switch are acceptable if received in a Q.931 message, but are never sent by the DMS-250 switch.

  • Page 50: Call Reference

    The Called Party Number information element is the digits dialed to access a terminal in the public switched telephone network or the private network. For details on how the DMS-250 switch uses the Called Party Number for routing the call, refer to “Translations and routing options” in Chapter 7, “Feature interaction.”...

  • Page 51: Calling Party Subaddress

    Message structure and function 4-3 For more information on how the DMS-250 switch uses the Calling Party Number, refer to “Identifying call origin—calling number delivery” in Chapter 7, “Feature interaction.” Calling Party Subaddress The Calling Party Subaddress information element allows the originating user to further identify the calling user.

  • Page 52: Congestion Level

    D-channel does not contain B-channels, a release with cause is returned specifying channel not available. The DMS-250 switch will always identify the DS-1 interface explicitly when table PRIPROF has the function switch “XPLCTIID” datafilled, regardless of the number of DS-1 interfaces that comprise the PRI.

  • Page 53: Lower Layer Compatibility

    The Network-Specific Facilities information element indicates which network facilities are being invoked at the specified network. PRI supports the following call types from the PBX to the DMS-250 switch. (For more information on the call types listed, see Chapter 7, “Feature interaction.”)

  • Page 54: Notification Indicator

    4-6 Message structure and function preference to other information (for example, destination number, number plan identification, and so forth); checks are made to ensure that the call setup information is consistent with the network facilities requested for the call. Notification Indicator The Notification Indicator information element indicates or conveys information pertaining to a call.

  • Page 55: Restart Indicator

    7 travels across the network without interpretation. Transport of codeset 7 information from ISDN user to ISDN user by way of a single DMS-250 is supported for all calls. Codeset 7 supports all 256 information elements (#00–#FF). Table ISDNPARM is used for all supported messages on PRI originating and terminating agencies.

  • Page 56: Q.931 Message Descriptions

    4-8 Message structure and function Q.931 message descriptions Table NO TAG1 lists Q.931 messages in alphabetical order. Included are each message’s meaning, direction, event information, and (where applicable) the correlation of messages with traditional telephone events. The following list depicts the messages in the order of their appearance during regular call setup.
  • Page 57 INFO message. All subsequent USER INFO messages are discarded. A STATUS message is sent to the sender of the USER INFO message with the Cause, Coding Standard, and Location. —continued— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 58 4-10 Message structure and function Table 4-1 Q.931 message descriptions (continued) Message Meaning Direction Event information CONN Connect Sent by the called party to the Generated by the terminating network, and by the network side of the call when the call is to the calling party, to indicate answered.
  • Page 59 NOTIFY message is sent. the transfer notification is not delivered to the user that was alerting after the transfer. The message is delivered after the user answered the transferred call. —continued— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 60 4-12 Message structure and function Table 4-1 Q.931 message descriptions (continued) Message Meaning Direction Event information PROG Progress The network or the originator Indicates the progress of a call sends this message. during call establishment (for example, when the call has left the ISDN network or to indicate the use of in-band tones.
  • Page 61 Bidirectional; can be sent by Used to acknowledge changes acknowledge either the calling party or the to the status of PRI network. B-channels. Sent in response to a SERV message received. —continued— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 62: Q.931 Message Information Elements

    4-14 Message structure and function Table 4-1 Q.931 message descriptions (continued) Message Meaning Direction Event information SETUP Setup Sent by either the originator or Sent to the network when a call the network to initiate call is initiated; this message establishment.
  • Page 63 DISConnect message with cause value #31, “normal, unspecified” was received. User to user Both Optional FAC ACK Protocol Discriminator Both Mandatory —continued— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 64 4-16 Message structure and function Table 4-2 Q.931 message information elements (continued) Q.931 message Information element Direction Type Call Reference Both Mandatory Message Type Both Mandatory Network-Specific Both Optional Facilities FAC REJ Protocol discriminator Both Mandatory Call Reference Both Mandatory Message Type Both Mandatory...
  • Page 65 PROG Protocol discriminator Both Mandatory Call reference Both Mandatory Message type Both Mandatory —continued— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 66 4-18 Message structure and function Table 4-2 Q.931 message information elements (continued) Q.931 message Information element Direction Type Cause Both Optional; supplied when there is in-band treatment applied to the call and there is a cause that corresponds to that in-band treatment;...
  • Page 67 D-channel are to be restarted, it is not included. SERV ACK Protocol discriminator Both Mandatory Call reference Both Mandatory Message type Both Mandatory Change status Both Mandatory —continued— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 68 4-20 Message structure and function Table 4-2 Q.931 message information elements (continued) Q.931 message Information element Direction Type Channel identification Both Optional; mandatory only if a single channel or a single interface controlled by a D-channel is to be restarted. If all the channels associated with a D-channel are to be restarted, it is not included.

  • Page 69: Q.932 Message Descriptions

    Table 4-3 lists the Q.932 messages in the order they appear during regular call setup. Included are each message’s meaning, direction, event information, and (where applicable) the correlation of messages with traditional telephone events. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 70: Q.932 Message Information Elements

    4-22 Message structure and function Table 4-3 Q.932 message descriptions Message Meaning Direction Event information FACILITY Facility Sent by a user to a network to Network dependent. Refer to request the supplementary the appropriate network profile service or from the network to supplement to determine what the user to respond to a level of message is supported...

  • Page 71: Congestion And Network Flow Control

    Status messages are not generated during user congestion. All user information messages are discarded. Network Flow Control Flow control of User Information messages at the DMS-250 switch is done using the following algorithm: burst parameter X, initialized to office parameter UUS_BURST...
  • Page 72 “Receiver Not Ready”. If the access DMS-250 goes into “network congestion” due to congestion flow control, the DMS-250 will send its access user a Congestion Control message with an indication of “Receiver Not Ready.” If the far end user is congested, it sends a Congestion Control message with an indication of “Receiver Not Ready.”...

  • Page 73: Call Control Procedures

    Chapter 4, “Message structure and functions.” DMS-250 switch functions and services The DMS-250 switch provides the following functions and services: authorization of the call by collection and validation of — authorization codes (authcodes)—multidigit codes used to identify a...
  • Page 74 5-2 Call control procedures DMS-250 switch functions as a user or a network. For the DMS-250 switch, this parameter should be set to network. Figure 5-1 shows a call traveling from nodes 1 through 6 as it proceeds through the various nodes by means of PRI. At node 3 (call incoming on a PRI) is an originating exchange.

  • Page 75: Call Establishment At The Originating Exchange

    For call control procedures, there are only a few differences between the network side and the user side. The following information focuses on the DMS-250 switch as the network; any differences are stated. If the D-channel data link fails, start timer T309. If the timer expires, clear the network connection and release the B-channel and call reference.

  • Page 76: Call Types Supported

    VNET Calling card The DMS-250 makes various requests of the NCS for its services and waits for the NCS to respond. The information the NCS returns to the switch is used for: call translation...

  • Page 77: Translation Example

    LTCALLS.) For more information, refer to Chapter 7, “Feature interaction.” Call translation Before the DMS-250 switch can route a call, the switch must perform translation. Translation occurs when the DMS-250 switch access the information in a message signal and processes the information according to datafill tables.
  • Page 78 996 996 CT ONNET 7 7 0 TABLE HNPACONT POS 904 SUBTABLE HNPACODE 996 996 LRTE 15 SUBTABLE RTEREF 15 S D D2SPRI $ The name of the PRI trunk on the DMS-250 switch between the switch and the terminating PBX 297-2521-106 Standard 23.01 March 2001...
  • Page 79 The AUTHCODE field provides a means to bill calls originating on the PRI and is captured in the call detail record accordingly. Also, the AUTHCODE provides a way to indicate optional account code digits are required for calls originating on that call attribute. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 80: B-Channel Allocation And Negotiation

    STDPRTCT to locate the pretranslator subtable to use for the call. The pretranslator PRAX contains an entry for the dialed digits and, in this case, marks the call as call type ONNET. On the DMS-250 switch, ONNET calls are considered to be private. Marking the call type as ONNET or OFFNET changes the numbering plan indicator on the outgoing side of the call to either PRIVATE or E.164, respectively.

  • Page 81: Call Proceeding And Termination

    In the event that an outgoing route cannot be successfully allocated, a CALL PROC message may be sent to the originating PRI interface as described in “Call routed to treatment” in this chapter. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 82: Call Establishment At The Terminating Exchange

    Call establishment at the terminating exchange Call establishment at the terminating exchange occurs when a PRI call goes out from the DMS-250 switch (node 4 in Figure 5-4) when the switch is the network. In any PRI connection, one end of the interface functions as the user and the other functions as the network.

  • Page 83: Terminations And User Responses

    CONN ACK. (The user always receives a CONN ACK in response to a CONN sent to the network.) Figure 5-5 shows the message sequence between the network and the two users on a PRI-to-PRI call. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 84 5-12 Call control procedures Figure 5-5 Q.931 message sequence for PRI-to-PRI call setup Originating Terminating Network user user SETUP (CR,CID, NSF, CDN, CGN, DIE, OCN, RGN) CALL PROC (Translations and routing complete) SETUP (CR, CID, BC, NSF, CDN, CGN) CALL PROC ALERT ALERT NOTIFY...

  • Page 85: Termination To A Pbx

    “Call is not end-to-end ISDN” (as shown in Figure 5-6). If the DMS-250 switch is forced to reselect another non-ISDN trunk after terminating to a non-ISDN trunk, a second progress message is sent. If the call reselects a PRI trunk group, the call remains “not end-to-end ISDN”...
  • Page 86 5-14 Call control procedures CONN message—If the network receives an indication from the outgoing trunk that the far end has answered, a CONN message is sent out over the originating PRI interface. The originator responds with CONN ACK. (The user receives a CONN ACK in response to a CONN sent to the network.) Figure 5-6 shows the message sequence between the network and the originating PRI interface when the terminator is a non-ISDN trunk.
  • Page 87 Note: Dashed lines indicate optional messages. Audio tone detectors Audio tone detectors (ATD) provide a means for the DMS-250 switch to detect an answer on a circuit that does not support supervisory signals for hardware answer. Audio signals generated from the called party determine when the called party has answered.

  • Page 88: Termination To Enhanced Voice Services Aru

    5-16 Call control procedures While PRI agencies do not support the use of ATDs to monitor answer on PRI-terminated calls, they may connect to an agency that does support ATDs. In this case, the PRI reports an answer when the ATD indicates that an answer is received from the called party.
  • Page 89 Scenario 1: Terminating DMS-250 billing record is used to bill the call when INWATXLA=N. Terminating DMS-250 Originating trunk class = operator service trunk Terminating trunk class = operator service trunk Scenario 2: Terminating DMS-250 billing record is not used to bill the call when INWATXLA=Y. Terminating ISUP DMS-250 DMS-250...
  • Page 90 5-18 Call control procedures Termination capability EVS termination capabilities are provided for a call if one of the following occurs: an EVS feature code is included in the network control system feature code parameter (returned to the originating switch in the routing response message) the NARSCALL field of table INWATXLA is set to Y (EVS was previously called NARS—network audio response system)
  • Page 91 The ability to transfer (extend) an active call from the EVS ARU to a new destination is supported for non-VNET calls, but not for VNET calls. The EVS system can instruct the DMS-250 switch to transfer a call as explained below:...
  • Page 92 5-20 Call control procedures Figure 5-11 Trunk release sequence of events EVS switch EVS ARU Transferred Incoming trunk call prior to releasing PRI trunks. Outgoing trunk EVS switch EVS ARU Incoming trunk Bridged call prior to releasing Outgoing trunk PRI trunks. EVS switch EVS ARU Incoming trunk...
  • Page 93 The leg 1 SETUP message (as shown in Figure 5-12) includes the OTG and OSID values in the Generic Digits parameter. The leg 1 SETUP message also includes the value dialed number identification services in the Generic Digits information element. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 94: Reseller Switch Setup And Release

    5-22 Call control procedures The OTG, OSID, and DNIS values are taken from the ISUP IAM message that comes from the originating switch. The Generic Digits parameter and Generic Address information element allow the EVS switch to deliver digits to the end user. Reseller switch setup and release A normal call setup and release using a reseller switch is shown in Figure 5-13.
  • Page 95 Conversation Conversation Note: Dashed lines indicate optional messages. The DMS-250 switch indicates that it is ready to accept SUPPCODE digits from the reseller by sending a 400-Hz prompt tone. Any digits dialed before this prompt tone are ignored. The collection period can timeout and cause an in-band treatment due to permanent signaling or partial dial.

  • Page 96: Call Takedown For Normal Call Clearing

    PARTDIAL for partial dial. The DMS-250 switch ignores any digits dialed after a timeout. The DMS-250 switch also ignores the DTMF signals * and #; these digits cannot reset the timeout periods for partial dial or permanent signaling.

  • Page 97: Network-Initiated Normal Call Clearing

    — starts timer T305 and the lockout timer; the B-channel is not available for other calls After receiving a REL message from the user, the network cancels T305 and releases the B-channel and call reference. The B-channel is now available Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 98: Disconnection Of An Evs Call

    5-26 Call control procedures for other calls. The network sends a REL COM message to the user, as shown in Figure 5-15. Figure 5-15 PRI-to-PRI disconnect, network initiates normal call clearing Network User DISC Free the NETWORK connection. The trunk member is idled; the B-channel is disconnected;...
  • Page 99 Figure 5-17 illustrates an EVS-initiated call disconnect message sequence. Figure 5-17 EVS-initiated call disconnect Originating (ISUP) (PRI) EVS switch switch FACILITY (FAC IE, INV 1, NARS BLG, menu billing info) FACILITY DISC REL COM Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 100 DISC (cause) REL COM REL COM The DMS-250 switch supports a two-message release sequence when handling abnormal error conditions. This sequence involves a REL–REL COM sequence of messages. The net results are identical to the three-message release sequence (the release sequence begins with a DISC message).

  • Page 101: Cause And Treatment Handling

    (this includes mapping action codes from a failure response to a treatment) when one of the following message types are received by the DMS-250 switch (with causes not equal to 16): — ISUP RELease with cause —...

  • Page 102: Standard Cause And Treatment Handling

    Alternate treatments The DMS-250 switch can also specify that all calls routed to treatment from a PRI route according to the information datafilled in the ALTERNATE subtable of TMTCNTL. This takes the place of the reference to the PRA250 subtable and precludes the possibility of referencing both subtables.

  • Page 103: Enhanced Cause And Treatment Handling

    The expanded PROTOCOL field contains the following choices: Q764, TR394, TR444, A607, Q931, BUSY, ALL, PROT1, and PROT2. Datafill A “Y” in the CSE_TRMT_ENHANCEMENTS parameter selects the Enhanced cause and treatment handling feature. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 104: Q.931 Cause Values

    5-32 Call control procedures Q.931 cause values If a call originated by a PRI interface cannot be completed by the DMS-250 switch (for example, the terminator is busy, or no circuits are available to route the call), one of the following occurs: If the switch treatment maps to a Q.931 cause value—The cause value is...

  • Page 105: Mapping Of Cause Values To Treatment

    DMS-250 switch or transported as received. Mapping of cause values to treatment Table 5-2 lists the cause values mapped to DMS-250 switch treatments, and the corresponding treatments applied. Table 5-2 Cause-to-treatment mapping...
  • Page 106 5-34 Call control procedures Table 5-2 Cause-to-treatment mapping (continued) Cause Cause Treatment number No user responding No_terminal_responding (NTRS) User alerting, no answer Reorder (RODR) Call rejected Restricted_date_time (RSDT) Number changed Call_not_accepted (CNAC) Destination out of order Reorder (RODR) Invalid number format Partial dial (PDIL) Facility rejected Feature_action_not_acknowled...

  • Page 107: Mapping Of Treatments To Cause Values

    Reorder (RODR) —end— Mapping of treatments to cause values More than one treatment may generate a specific cause value. Most of the DMS-250 switch treatments map to meaningful cause values. All remaining Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 108 Table 5-3 lists treatments and the corresponding cause values. For definitions of the treatments, see the DMS-250 Customer Data Schema Reference Manual. All treatments not listed map to the cause value unknown (127).

  • Page 109: Exception Conditions

    —end— Exception conditions Exception conditions that occur include B-channel glare, B-channel lockout, no response to SETUP, no response after a CALL PROCeed message, and protocol violations. These are described as follows. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 110: B-Channel Glare

    Glare is the simultaneous seizure of a trunk at both ends. Glare occurs when the DMS-250 switch tries to select an idle PRI trunk member for termination just as a SETUP message is being received from the PBX requesting the same trunk member.
  • Page 111 B If BCHGLARE is datafilled as YIELD (BCHGLARE = YIELD), the DMS-250 switch allows the origination to proceed on the PRI trunk member and responds to the SETUP message in the same manner as for regular call setup.

  • Page 112: B-Channel Lockout

    User-initiated call clearing If the DMS-250 switch internal lockout timer expires before a REL COM message is received, the network puts the trunk member in the lockout state. If the REL COM message is received before timer T308 expires, the trunk member is returned to idle from the lockout state.
  • Page 113 If the lockout timer expires before a REL message is received, the network puts the trunk member in lockout state. If timer T305 expires before a REL Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 114: No Response To Setup Message

    5-42 Call control procedures message is received, the network sends a REL message to the user and starts timer T308 while waiting for REL COM. If the REL COM message is received before timer T308 expires, the trunk member is returned from the lockout state to idle.

  • Page 115: No Response After A Call Proc Message

    If the DMS-250 switch receives a REL or DISC message with any of these cause values, it reselects or route advances. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 117: Pri Interworking

    T100, T101, T102, T104, T105 FGD DAL Originators The following originators are supported when the call terminates to a PRI: DAL (FXO, FXS) DAL TIE TRUNK FGD (PTS and SS7) CAMA/VNET CAMA Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 118: Enhanced Digital Recorded Announcements

    6-2 PRI interworking ISUP IMT (reseller standard, reseller option 1, reseller option 2, ISUP RLT) T100, T101, T101 IC, T102, T104, T105 FGD DAL Enhanced digital recorded announcements This feature supports the use of enhanced digital recorded announcement machines (EDRAM) to provide announcements to PRI interfaces. EDRAMs may be used to specify a route list or to specify an announcement to be applied to a treatment.
  • Page 119 The CCS7 network cuts through PCM in both directions upon propagation of the Address Complete Message. The terminating exchange (either ISDN or non-ISDN) provides the ringback tone. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 120: Pri-To-Isup-To-Pri

    The call scenario in Figure 6-2 illustrates two-stage call clearing whereby a Q.931 REL message maps into the ISUP REL message at the interworking switch initiating call clearing (that is, the calling-access DMS-250 switch) and an ISUP REL message maps into a Q.931 DISConnect message on the other interworking switch (the called-access DMS-250 switch).
  • Page 121 The ISUP REL message is mapped to Q.931 REL at the calling-access DMS-250 switch. Figure 6-3 Unsuccessful call attempt (user busy) (PRI) (PRI) (ISUP) DMS-250 DMS-250 SETUP SETUP CALL PROC CALL PROC Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 122 The call shown in Figure 6-4 is an example of the interworking with the in-band tone and announcement applied within the network as a result of a treatment. Figure 6-4 PRI-to-ISUP-to-PRI call treatment (PRI) (ISUP) (PRI) DMS-250 DMS-250 SETUP treatment CALL PROC occurs Cut-through PROG...

  • Page 123: Non-Isup Trunks

    DMS-250 DMS-250 DMS-250 SETUP Seizure CALL PROC Digits SETUP CALL PROC PROG PROG/ALERT Ringing CONN Answer CONN CONN ACK CONN ACK Active call DISC On-hook DISC On-hook REL COM REL COM Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 124: Pri-To-Pts

    The ACM is then mapped to a progress at the calling-access switch. Figure 6-6 — Interworking between PRI and PTS trunk PRI-to-PTS (ISUP) (PRI) (PRI) (PTS) DMS-250 DMS-250 SETUP SETUP Seizure Digits CALL PROC CALL PROC PROG PROG...

  • Page 125: Pts To Pri

    Previously, OLI to ISDN PRI was not supported. OLI is now available by way of the Locking Shift Codeset 6 parameter. The codepoint can be set to any value in the range from 00 to 7F (hex) within the Codeset 6 parameter. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 126: Oli Delivery On Pri Termination

    6-10 PRI interworking OLI delivery on PRI termination OLI information is delivered to the ISDN PRI trunk by way of Locking Shift Codeset 6 parameter in the call SETUP message. The SETUP message for ISDN PRI is shown in table 6-2. The codepoint value in which OLI is delivered is the value that is datafilled on a per trunk basis in table CALLATTR.
  • Page 127 PRI interworking 6-11 Table 6-2 SETUP Message for ISDN (continued) Information Element Type Length Locking Shift to Codeset 7 Codeset 7 Parameters 2–* Note: * = DTMF Delimiter —end— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 129: Feature Interaction

    With integrated services access (ISA), any open circuit can originate or terminate any subscribed service. With this service-based architecture, calls originating over an ISA PRI facility are handled based on the call type. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 130: Call Types Supported

    7-2 Feature interaction Call types supported The call types supported for calls coming into the DMS-250 switch include PRISM, TIE (trunk connection between two PBXs), VNET, SAC (800, 900), and direct termination facilities over a single PRI. Call types supported for outgoing calls on the DMS-250 switch include: PRISM—generic service for public calls translated in-switch;...

  • Page 131: Pri Origination And Call Type

    SETUP message. PRISM If the incoming NSF information element is set to PRISM, the call is treated as a public call type. When the NPI in the called party number information Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 132 DMS-100 or SL-100 with an unsupported NSF value, the call proceeds after the originating DMS-250 switch receives the associated STATUS message. If a call originates on a DMS-250 switch and terminates to an SL-1 with an unsupported NSF value, the call is taken down.

  • Page 133: Pts Origination And Terminating Pri Call Type

    Routing Response: NSF=800/900 Remote Access Response: NSF=VNET DDD/IDDD Response: NSF=PRISM Destination PTS origination and terminating PRI call type The DMS-250 switch can assign the following call types for PTS trunk originations. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 134: Call Type Mapping

    For pretranslated 800 or 900 calls, the DMS-250 switch routes according to table INWATXLA. If the information is unavailable or insufficient to route a call, the DMS-250 switch sends a requests to the NCS for real-time database translation. Call type mapping...
  • Page 135 VNET (from PRI or PTS trunk) VNET PRISM PRISM (from PRI or PTS trunk) PRISM 800 or 900 (from PTS trunk) 800 or 900 —end— Table 7-2 lists the mapping from PTS originations to PRI NSF. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 136: Translation And Routing Options

    800, or 900. —end— Translation and routing options The DMS-250 switch offers two options for processing incoming PRI calls: IEC translation and routing (XLAIEC) and direct ISA route reference routing (ISA RTEREF). The assignment of a call to either XLAIEC or ISA RTEREF is based on call type.
  • Page 137 Each LTID/call type combination may have unique parameters associated with it, providing for a multiple of unique ISA RTEREF combinations. The LTCALLS fields required to invoke ISA RTEREF routing are listed in Table 7-3. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 138 7-10 Feature interaction Table 7-3 Table LTCALLS fields required to invoke ISA RTEREF routing Field Meaning Description LTID Logical Provides the first part of the 2-part key into terminal LTCALLS. Each LTID is associated with a PRI identifier interface (trunk group) and is used to index into service-related parameters for the interface.
  • Page 139 PRISM XLAIEC IEC translation and routing XLAIEC processes calls using procedures for DMS-250 switch digit interpretation, translations, screening, and routing. (The XLARTE field should be datafilled with the value XLAIEC. This field specifies the call type will receive its translations and routing information from the IEC translations tables.)

  • Page 140: Off Network Dialing

    7-12 Feature interaction off-hook queuing IEC translation steps The following lists the steps that occur when the DMS-250 switch performs IEC translations on an originating PRI call. 1 LTCALLS obtained—LTCALLS is obtained from table TRKGRP. 2 Access LTCALLS info—Using the call type received in the incoming...
  • Page 141 North America without operator assistance. An IDDD number consists of the international access number (011), the country code (CC) (1–3 digits), and the national significant number. Table 7-5 shows the maximum number of digits allowed. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 142: On Network Dialing-Vnet

    7-14 Feature interaction Table 7-5 IDDD digits International dialing format Number of possible digits International access number 3 digits (011) Country code (CC) 1–3 digits National significant number (NSN) 1–11 digits Note: The maximum number of digits allowed for an IDDD number is 18. This includes the 011 international access number.

  • Page 143: Public Speed Dialing-Ddd/Vnet

    Ten-digit routing allows a tandem switch to terminate calls. Tandem switch termination avoids the access and egress charges that occur when the call is routed by switches owned by local exchange carriers. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 144 7-16 Feature interaction Ten-digit routing on a call is done by means of indexing the call through a series of tables and subtables. The following are the subtables and tables involved in ten-digit routing: subtable FNPACODE (under FNPACONT) or HNPACODE (under HNPACONT) subtable RTEREF (under FNPACONT or HNPACONT) table TENDTSCR...
  • Page 145 Each index in table TENDTSCR can have up to 128 such ranges associated with it. 5 Table TENDTSCR maps the index and the XXXX range to a line in table TENDRTE. Table TENDRTE routes the call onto an outgoing trunk. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 146: Test Calls

    7-18 Feature interaction Test calls DMS-250 switch test calls enable various manual and automatic tests from distant toll and local offices without intervention at the called office. The test line presents known conditions upon connections being made to them. Test line test calls can be originated manually from the trunk test position (TTP), or automatically in automatic trunk test.

  • Page 147: Time-Of-Day Routing

    (field TIMEBIAS). This field specifies whether to add or subtract up to 12 hours in one-hour increments from the DMS-250 switch time to calculate the call origination date and time. Calls failing restricted usage by date and time screening are blocked and given restricted usage treatment.

  • Page 148: Trunk Group Class-Of-Service Screening

    PRI calls, regardless of whether ISA direct routing is performed. Retranslation The DMS-250 switch currently provides the ability to assign an outgoing route selector as the RX route selector. This means that calls terminating to that route are capable of retranslating, and choosing another outgoing route.

  • Page 149: Data Calls

    Feature interaction 7-21 transmission required. (For more information on bearer capability, see Chapter 4, “Message structure and functions.”) The DMS-250 switch supports the following bearer capabilities for PRI trunks: speech 56 kbit/s unrestricted 64 kbit/s unrestricted 64 kbit/s restricted 3.1 kHz audio When terminating to a PRI, the BC information element passes unchanged unless the call has been marked as data through translations.

  • Page 150: Data Call Cause Handling

    No restriction is applied to calls destined to non-IMT trunks. Data call cause handling For all data calls, the DMS-250 propagates the non-normal cause parameter or cause information element received in one of the following messages from the terminating agency:...

  • Page 151: Route Advancing

    Route advancing For all data calls, route advancing occurs if any of the following cause values are received at a terminating DMS-250 switch (and therefore the terminating agency is not an MCI ISUP IMT): 34—no circuit available 41—temporary failure 42—network congestion...

  • Page 152: Setup Message

    7-24 Feature interaction SETUP message When a SETUP message is received, the network checks to see whether the calling number information element is included. If so, it is captured in the ANI field in the appropriate billing record. (PRI delivers pseudo-ANI for FGC trunks.) SETUP contains calling number If the calling number information element is included in the SETUP...

  • Page 153: Pts-To-Pri Call

    Feature interaction 7-25 PTS-to-PRI call The DMS-250 switch may receive the ANI from the following originating agencies: centralized automatic message accounting PRI delivers pseudo-ANI for FGC trunks. If PRI termination from these agencies is required, the following rules for calling number delivery are applied, depending on the CPIALLOW value in...
  • Page 154 CDR, this is in word 27, bits 0 to 3; for the PNR, this is in word 15, bits 6 to 9. Figure 7-8 shows calling number delivery within the SS7/ISDN network. Figure 7-8 Calling number delivery in the SS7 network (PRI) (ISUP) (PRI) DMS-250 DMS-250 (CPIALLOW=YES) SETUP SETUP CALL PROC CALL PROC ALERT...

  • Page 155: Prism Service

    Call processing If the NSF parameter in the incoming SETUP message indicates PRISM service, the DMS-250 switch initiates the originating DAL call processing. If required, the switch performs DTMF digit collection of supplemental code (suppcode) and/or account code. Depending on the subscription parameters of the PRI interface, treatment-to-cause mapping may be performed (as described in Chapter 5, “Call control procedures”).
  • Page 156 7-28 Feature interaction Table 7-8 PRISM conflict dialing plans Field Dialing plan 7D VNET NXX-XXXX 10D VNET 1 + NXX-NXX-XXXX 10D DDD 1 + NXX-NXX-XXXX IDDD 011 + CC + NN HOTLINE 7/10D VNET or DDD dialing plans filed against the authcode in AUTHCODM N = 2–9;...

  • Page 157: Vnet Services

    The following VNET features are supported: 7D and 10D VNET dialing 10D and international direct distance dialing (IDDD) standard translations originating direct termination overflow conflict dialing or nonconflict dialing enhanced overflow VNET hotlines Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 158 7-30 Feature interaction supplementary code redial enhanced reorigination Dialing plans The VNET dialing plans driven by pretranslation and supported by this feature are described in Tables 7-10 and 7-11. Table 7-10 VNET conflict dialing plans Field Dialing plan 7D VNET NXX-XXXX 10D VNET 1 + NXX-NXX-XXXX...

  • Page 159: Call Processing

    (ANI); provided if received in the calling number information element of the SETUP message NCS response After translating the called number, the NCS/DAP responds to the DMS-250 switch for call completion with a routing response—A successful translation of the VNET call occurred if the NCS sends a routing response to the originating switch.

  • Page 160: Translation And Routing

    ID, the NCS/DAP sends the response with the terminating trunk group number, subsequent address number, and other routing information. After the DMS-250 switch receives this information, it attempts to complete the call over the terminating trunk group number received in the NCS/DAP response.

  • Page 161: Sac Service

    800 and 900 service The DMS-250 switch receives 800 and 900 service calls over FGC and FGD trunks. The 800 or 900 services calls are routed to the terminating switch along with the ten-digit ANI (if received at the originating switch). If the terminating trunk in the terminating switch indicates ISDN PRI, the DMS-250 switch sends a SETUP message with optional ANI.

  • Page 162: Authorization Codes

    On the DMS-250 switch, each call that originates over a PRI is associated with an authcode. For PRI, this association is performed by table CALLATTR.

  • Page 163: Filed Hotline Numbers

    Filed hotline numbers The DMS-250 switch allows the option to file hotline numbers against a subscriber’s authcode. If an authcode is a “hotline,“ all calls originating on that trunk group are automatically placed to a predetermined number without the subscriber having to enter any digits.

  • Page 164: Supplementary/Account Codes

    Voice call suppcode/account code collection If the DMS-250 switch receives a voice call requiring a suppcode, it sends a 400-Hz prompt tone, then collects and processes the number. Data call suppcode/account code collection If the DMS-250 switch receives a data call requiring supplementary or account code collection, it does not send a prompt tone;...
  • Page 165 Field Example Datafill LTID ISDN 1 VNET XLARTE XLAIEC CALLATTR TABNAME LTCOPT MLTIDX 1 —end— Collection flow The flow diagram in Figure 7-10 shows supplementary/account code collection for PRI data calls. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 166 In-switch versus out-of-switch digit collection When the DMS-250 switch receives a data call with an account code greater than zero (ACCTLEN field in table AUTHCODM > 0), it processes the call as in-switch. If the data call has an account code less than or equal to zero...
  • Page 167 Feature interaction 7-39 In-switch: VNET versus non-VNET When the DMS-250 switch receives an in-switch VNET data call requiring an account code, it attaches an indexed account number according to the value of the SUPPREQ field in table CALLATTR. The following table shows SUPPREQ functionality.
  • Page 168 7-40 Feature interaction Out-of-switch, non-VNET data calls are routed to their destination without SUPPCODE processing. Suppcode/account code truncation The supplementary or account code used is truncated from the right if one of the following is true: The number of digits datafilled in the SUPPCODE field of table MLTATTR is greater than the number of digits datafilled in the ACCTLEN field in table AUTHCODM.

  • Page 169: Overflow Call Control

    AUTHCODM is greater than zero (indicating in-switch account code collection) and NCS returns a message indicating out-of-switch supplementary code collection is required. Overflow call control Two types of overflow call control are available with the DMS-250 switch: direct termination overflow enhanced overflow Direct termination overflow Direct termination overflow is the control by the terminating switch of overflow processing and intiation of overflow transaction.

  • Page 170: Enhanced Reorigination

    ENHANCED_OVERFLOW field in table OFCOPT. can only be enabled on a DMS-250 switch with 9.X billing works with both VNET and SAC calls with NCS/DAP-based non-validated suppcode collections For further information on overflow functionality, refer to the Common Channel Signaling 7 Reference Manual.

  • Page 171: Network Call Transfer

    The following applies to user-to-user information (UUI): Customer premises equipment that is connected to the DMS-250 switch (with PRI) transports the user-defined information by means of one or more User-to-User information elements within the User Information message.

  • Page 172: Call-Associated Uui Signaling

    SETUP message is sent. UUI signaling confirms UUI feature capability for the receiving CPE, congestion level of the receiving CPE and the DMS-250 switch, the transfer of UUI message, and temporary signaling connection clearing.
  • Page 173 ISUP message Feature request NSF IE in NSF parameter in Setup message Initial Address Message Positive acknowledgment NSF IE in Facility Indicator parameter Facility Acknowledge in Facility Accepted message message —continued— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 174: Message-Associated Uui Signaling

    7-46 Feature interaction Table 7-16 Call-associated UUI signaling stages and messages (continued) Signaling stage PRI message ISUP message Transfer of user information UUI IE in UUI optional parameter in User Information message User (USR) message More Data IE in Enveloped within the User Information message optional Access Transport Parameter in the USR...
  • Page 175 Alerting (UUI IE) Connect (UUI IE) ANM (UUI Parm) Connect (UUI IE) Connect ACK Connect ACK Disconnect (UUI IE) REL (UUI Parm) Disconnect (UUI IE) Release Release Release Complete Release Complete Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 176: Datafill

    7-48 Feature interaction Datafill The datafill settings for UUI signaling include: Allow/disallow feature Both CAUUI and MAUUI signaling setup are controlled by fields of table LTDATA, as follows: CAUUI2—controls call-associated user-to-user signaling at setup CAUUI3—controls call-associated user-to-user signaling after setup MAUUI—controls preferred message-associated user-to-user signaling MAUUI and U1RQ—controls required message-associated user-to-user signaling...

  • Page 177: Ncid Generation

    For calls originating on an EVS PRI: If the call is extended from the EVS to another switch, the EVS DMS-250 switch generates a new NCID to be transported on the second leg of the call. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 178: Passing The Ncid

    7-50 Feature interaction The incoming PRI SETUP message will not contain an NCID; however, the DMS-250 switch will generate one. This is an example of an NCID generating at an intermediary switch. Passing the NCID During the progress of a call, the NCID is passed as follows:...
  • Page 179 CAMA trunks. VNET CAMA originations are treated the same as VNET DALs. VNET or 800 calls—can originate on a DAL HOTLINE. Originating agencies supported by this feature are shown in Table 7-17. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 180: Virtual Trunk Elimination

    If a call is not intended to terminate at an EVS switch, the call is routed from table VPNIMTRT. RLT/ATP This feature allows the DMS-250 ISUP network to transport the Access Transport Parameter (ATP) on Release Link Trunks (RLT) in the IAM, and to the Facility Redirect (FAR) messages. The RLT/ATP feature affects redirect and bridging calls and provides the ISDN with the ability to transport the ISUP ATP for calls that interwork with ISUP RLT trunks.
  • Page 181 ISDN with the ability to transport the ISUP ATP for calls that interwork with ISUP RLT trunks. When a FAR message is received with ATP at a DMS-250, the outgoing IAM from the DMS-250 copies the ATP from the incoming FAR to the outgoing IAM for ISUP termination.

  • Page 182: Fraud Call Interrupt

    7-54 Feature interaction Figure 7-15 ATP traversing the ISUP network DMS–250 ISDN DMS–250 ISUP Network RLT Platform DMS–250 DMS–250 DMS–250 ISUP ISUP Originating Terminating Node Node Fraud Call Interrupt The Fraud Call Interrupt feature allows an ISN application to identify a fraudulent call, initiate a special “Interrupt Call Order,”...
  • Page 183 Super Generic Digits (SGD) of an incoming ISUP Initial Address Message (IAM). Figure 7-16 shows the method of handling a fraudulent call through an ISUP facility. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 184: Interactions

    7-56 Feature interaction Figure 7-16 Method of handling a fraudulent call through an ISUP facility Incoming ISUP FAC (CIC=#3FFF) Service Activation Ignore set for Fraud Call? ISUP Facility Message Send return ISUP FAC indicating Fraud Call Interrupt Fraud_Interrupt_Active Service Action Denied, set to Y? No Action Taken Ignore ISUP FAC...

  • Page 185: Datafill

    MCI ISUP IMT. For table TRKSGRP, the protocol field must be set to MCI. To activate the Fraud Call Interrupt feature, set the office parameter FRAUD_INTERRUPT_ACTIVE, which resides in the OFCVAR table, to Y. The default is N. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 187: Dialable Wideband Service

    ETS card for NT6X01AA. The digital trunk controller (DTC) for ISDN allows the provisioning of ISDN PRI trunks on the DMS-250 switch system. The DTC ISDN (DTCI) provides a maximum of 20 T1 spans, each of which contains 24 channels.

  • Page 188: Trunk Types

    8-2 Dialable Wideband Service Figure 8-1 Relationship of DTCIs, channels, and spans T1 spans DMS-250 DS-0 switch (up to 20 per DTCI) channels (24 per T1 span) DTCI (19) (20) Trunk types The following trunk types, shown in Figure 8-2, are used in DWS:...

  • Page 189: Translating And Routing

    FGD. ISUP FGD originations can terminate on all three of the available trunk types. Translating and routing The DMS-250 switch translates incoming wideband calls and routes outgoing wideband calls by performing the following functions: determine the channel requirements determine the protocol of the call...

  • Page 190: Constraints

    8-4 Dialable Wideband Service Constraints The following constraints apply to processing wideband calls: The trunk group must be either ISUP FGD, PRI, or MWC ISUP-IMT. The SELSEQ field in Table TRKGRP must be set to wideband. The selector in the route list must be supported for wideband services. Group reset circuit is supported but not with respect to a controlling or non-controlling channel or when it has a channel assignment map.

  • Page 191: Signaling

    The information contained in the SETUP message lets the switch know how to handle the data transfer of the wideband call. The manner in which the DMS-250 switch handles the data transfer is established in datafill of the switch database.
  • Page 192 The CID information element identifies the channel(s) to be used in the wideband call, the type of interface, the coding standard, and the channel type (B, H0, or H11). If there are no protocol violations, the DMS-250 switch reads the CID information element to allocate the channels indicated in the CID information element.

  • Page 193: Selecting A Route

    Information Indicator channel selection Selecting a route When selecting a route for the wideband call, the DMS-250 switch performs a search based on grouping—searching trunks for the channel grouping required (the channel range to be dedicated to the wideband service) sequence—channel selection in either ascending or descending sequence...

  • Page 194: Channel Selection Sequence

    Flexible allocation—a selection option of 2–24 DS-0s on a T1 span Channel selection sequence The DMS-250 switch uses either of two algorithms to search for idle trunks on which to route wideband calls: wideband bestfit ascending sequence (ASEQ)—starts the channel search...

  • Page 195: Channel Availability Selection

    The system deletes a T1 from the list when its last channel is deleted from Table TRKMEM. Channel availability selection The DMS-250 switch can be set to look for either of the following: bestfit—searches for the smallest block of idle channels that fulfills the requirements of the wideband call This search will initially skip over a large block of idle channels in a T1 to find a smaller block on which to route the call.

  • Page 196: Datafill For Channel Selection

    8-10 Dialable Wideband Service firstfit—searches for the first available idle channels that fulfill the requirements of the wideband call; this option minimizes the possibility of glare. Datafill for channel selection Tables TRKMEM and TRKGRP establish the protocol, circuit requirements, and trunks for DWS. The combination of these assignments determine the type of circuit used for the wideband call.

  • Page 197: Datafill Values

    Dialable Wideband Service 8-11 Table 8-1 shows an example of how datafill relates to channel selection. In this example the DMS-250 switch selects 6 or 24 contiguous and bounded B-channels as fixed selection (for example, six B-channels that begin and end on fixed time slot boundaries of 1–6, 7–12, 13–18, or 19–24).

  • Page 198: Fragmentation

    8-12 Dialable Wideband Service Fragmentation Fragmentation occurs when the total of B-channels over all the T1 spans is enough to accommodate a request for wideband services, but there are not enough B-channels on any single T1 to accommodate the request. If a call requires more channels than are available on the first T1 of the route list, the call advances to the next T1 of the list.
  • Page 199 Route list—It is not recommended or supported that the same trunk group be placed in the same route list more than once; this greatly increases the chances that glare will occur. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 201: Datafill And Subscription Parameters

    DMS-250 switch and their datafill. PRI subscription parameters allow customers to support and configure PRI to their particular needs. The DMS-250 switch assigns the parameters by datafilling a set of software tables. At the end of this chapter, there is information about the CI command DISPDCH.

  • Page 202: Facility-Related Interface Parameters

    9-2 Datafill and subscription parameters the common language location identifier (CLLI) and the logical terminal identifier (LTID). The CLLI identifies the PRI interface as a unique trunk group, together with associated subgroup and member data. The LTID functions as the key to the various service-related tables. Together they completely define a PRI interface.

  • Page 203: Service-Related Interface Parameters

    (facility data) Database correlation A number of database items must be correlated in the DMS-250 switch to ensure a properly functioning PRI. This includes configuration data correlation, layer 1 data correlation, layer 2 data correlation, layer 3 facility data correlation, and layer 3 service data correlation.

  • Page 204: Layer 2 Data Correlation

    9-4 Datafill and subscription parameters Table 9-1 Layer 1 database correlation Description DMS-250 switch (Table CARRMTC) Card type Field CARD Value: NT6X50AA, NT6X50AB, or NT6X50EC Frame format Field FF Superframe Value: SF Extended superframe Line encoding Field ZLG Zero code suppression...

  • Page 205: Layer 3 Facility Data Correlation

    Value: 2 B-channel selection Table TRKGRP Field SELSEQ Value: ASEQ, DSEQ, or WIDEBAND Loss and level Table TRKGRP Field PADGRP Value: NPDGP User-network interface Table TRKSGRP Field IFCLASS Value: NETWORK —continued— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 206: Layer 3 Service Data Correlation

    Datafill tables Tables are datafilled from top to bottom. Figure 9-2 shows the interdependencies of tables within the DMS-250 switch and the resulting datafill order. Tables at the same vertical position (as shown in in Figure 9-2) can be datafilled in parallel.
  • Page 207 LTDEF MLTATTR LTMAP LTCALLS Table CLLI The codes (maximum of 1024) in Table CLLI (Common Language Location Identifier) uniquely identify the far end of each: announcement service circuit test trunk tone Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 208 TRAFUNIT (three characters)—TRAFFic UNIT; identifies the designation of the traffic unit at the far end of the trunk group. (This is not currently used for the DMS-250 switch) SUFX (one character)—SUFfiX; uniquely identifies trunk groups that terminate at the same CLLI location. (This is not currently used for the DMS-250 switch.)
  • Page 209 Datafill and subscription parameters 9-9 The value of ADNUM must be unique. Attempts to add a CLLI code with an ADNUM already in use are rejected. For restrictions on modifying the ADNUM field, see DMS-250 Data Schema Reference Manual. TRKGRSIZ field The TRKGRSIZ (TRunK GRoup SIZe) field contains a numeric value in the range of 0 to 2047.
  • Page 210 9-10 Datafill and subscription parameters Table 9-4 Table CLLI example field entries (continued) CLLI ADNUM TRKGRSIZ ADMININF OTWAON2323H1 LA.54.LA FPOT LKOUT IDLE CF3P (Note 1) TERM102T (Note 2) TERM102L (Note 2) TERM100Q (Note 2) Note 1: This pseudo-fixed CLLI code is associated with the 3-port conference circuits in a toll switching unit.

  • Page 211: Ita Configuration

    Table LTCINV Table LTCINV maintains a list of line-trunk controller (LTC)-based peripherals that are datafilled in the DMS-250 switch. This table identifies the location of the ISDN digital trunk controller (DTCI) is located, the load and exec lineups required, and the network link connections.
  • Page 212 9-12 Datafill and subscription parameters Example: DS1PRA DEFAULT Table CARRMTC The attributes of DS-1 carriers are datafilled in this table and referenced from the DTCI P-side inventory Table LTCPSINV. Example tuple DTCI DEFAULT NT6X50AB MU_LAW B8ZS NILDL 1000 The DS-1 link can be configured in four basic operational modes: SF/ZCS SF/B8ZS ESF/ZCS...
  • Page 213 Busy and return the carrier to service. PRI facility-related tables Facility-related tables describe the characteristics of the PRI hardware interface and B-channel allocation. These parameters are datafilled in tables TRKGRP, TRKSGRP, and TRKMEM. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 214 9-14 Datafill and subscription parameters Table TRKGRP For all applications (PRI and non-PRI), Table TRKGRP defines data associated with each trunk group interface. Example tuple ML2DPR64CLD0 PRA250 NPDGP NCIT MIDL NIL 0 (ISDN00 VNET Fields of importance include the following: GRPTYP—used for call processing.
  • Page 215 PRI trunk. IFCLASS—describes this end of the PRI trunk as the network end or the user end of the protocol. The DMS-250 switch should always be datafilled as the network end. DCHNL—the main D-channel to be used for the PRI interface. It consists of: —...

  • Page 216: Pri Service-Related Tables

    9-16 Datafill and subscription parameters ITA configuration To configure ITA on DTCI, the non-PRI trunk groups must be datafilled in Table TRKSGRP along with PRI trunk groups. Table TRKMEM Table TRKMEM lists the data associated with each analog or digital trunk. For PRI, this table defines the B-channels in each trunk group.
  • Page 217 PROFILE—a vector of up to 64 function switch names. The default is NIL. Function switches for the profile vector To provide complete interworking between the DMS-250 switch and an SL-1, the following function switches have been implemented for protocol variants NTNAPRI and NTMCIPRI.
  • Page 218 9-18 Datafill and subscription parameters Important fields Important fields include the following: LTAP—the access privilege of the LT; must be B for PRI VARIANT—specifies the protocol variant for a particular interface ISSUE—contains a specific release of a PRI variant PROFNAME—The profile name contained in this field has been previously defined in Table PRIPROF.

  • Page 219: Ci Command-Dispdch

    The command DISPDCH is not supported for the DTCI D-channel handler (DCH). The following message is displayed when the CLLI corresponds to a DCH on a DTCI: There is no DCH associated with this trunk group. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 221: Service Verification

    To put PRI-related facilities into service, perform the following steps: 1 Ensure the carrier is in service (INSV). For more details on bringing a carrier into service, see “Verification of PRI facility on DMS-250 switch” in this chapter. 2 Ensure the PRI trunk is in service and idle (IDL).

  • Page 222: T100 Test

    10-2 Service verification In the T100 and T102 testline test descriptions, the terms on-hook and off-hook are used. These terms are not applicable for ISDN PRI trunks. A diagram of the TL100 configuration is shown in Figure 10-1. Figure 10-1 TL100 configuration Termi- Switch...

  • Page 223: Tl102 Tests Over Pri

    If the far end is a toll office, quiet termination continues until the near end releases the connection, or requests another test cycle (by means of a ring-forward signal). The milliwatt source-levels are office-dependent and trunk-group-dependent. ISDN PRI trunks do not support ring-forward. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 224: Call Over A Pri

    10-4 Service verification The operating sequence of the 102 testline is as follows: 1 Connect trunk under test to TTT. 2 Outpulse test code to far end office that returns off-hook. 3 The level meter of TTT measures milliwatt tone level and compares it with the expected measured loss (EML).
  • Page 225 LTID = ISDN_______ D–Channel DTCI_____ ______ ______ _______ Number of B–Channels_________ Call Attributes CDN_______________ NPI__________________ CGN___________________ DMS–250 Solution/Action Taken -250 no_fault found_ok miss_operate no_response mb/rts unable_to_reproduce database_table fris clear_when_tested CSR____________ clear_after_diagn Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 226 10-6 Service verification Figure 10-4 PBX Telecom Manager Trouble Report Form, page 2 Outside Plant Solution/ActionTaken FORWARDED TIME hrs. DATE CLEARED TIME hrs. DATE WORK DONE SWITCH PROBLEM = CMC LCM DTCI TERMINAL PROBLEM = OTHER HARDWARE PEC: ; SERIAL #: LOCATION: FAILURE ON SUSPECT HARDWARE...

  • Page 227: Pbx End-User Trouble Report Form

    ORIGINATION DN_______________ NUMBER DIALED_____________ CALL TRANSFER/CONFERENCE DN________________ HI&DRY WRONG–TERMINATION CUTOFF NOISY CROSSTALK FASTBUSY 1WAY–CONVERSATION DIGIT–DISPLAY DATA–CORRUPTION OTHER SUPPLEMENTARY INFORMATION SYSTEM____________ LOC_____________ S/W RELEASE + ISSUE FREQUENCY IMPACT WORKAROUND FORWARD TO FORECAST FIX Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 228: Verification Of Pri Facility On The Dms-250 Switch

    10-8 Service verification Verification of PRI facility on the DMS-250 switch This section defines the possible states for the following PRI components: PRI trunk carrier ISDN digital trunk controller (DTCI) D-channel PRI datafill verification The PRI-related tables fall into two categories: facility-related and service-related.
  • Page 229 The circuit is removed from service by system maintenance; system maintenance performs periodic tests. —end— Restoring service to the PRI trunk on the DMS-250 switch Table 10-2 lists the various actions to be taken based on trunk states shown at the DMS-250 switch MAP terminal.

  • Page 230: Interpreting Carrier States On The Dms-250 Switch

    - Return the circuits to service The PRI circuit is system The system will return the member to service busy. after test is completed. —end— Interpreting carrier states on the DMS-250 switch Table 10-3 lists DS-1 carrier states and actions. 297-2521-106 Standard 23.01 March 2001...
  • Page 231 From carrier level of the MAP terminal: return the carrier to service. Note the new carrier state. SYSB Carrier is system busy From carrier level of the MAP terminal: diagnose the fault. Note the new carrier state. —end— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 232: Interpreting Pri Dtci States

    DTCI out of service. —end— Restoring service to the DTCI Table 10-6 lists DTCI states and actions. Table 10-6 DTCI states and actions DMS-250 Resource out of service Actions to be taken switch states MANB DTCI is manual busy...

  • Page 233: Interpreting Dch States

    This state indicates a failure at the logical link level or the hardware (not the carrier). Remote not responding This state indicates that CCS7 layer 3 at the far end is not responding (RNR) although CCS7 layer 2 is established and ready. —end— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 234 When the DCH state is LO or RNR, refer to “Troubleshooting” in Chapter 3, “D-channel handler,” for additional information on troubleshooting. Table 10-8 lists the DCH states and actions. Table 10-8 DCH states and actions DMS-250 Resource out of Actions to be taken switch states service D-channel is installation - Enter the PRADCH level of the MAP terminal.

  • Page 235: Engineering Recommendations

    (that is, containing idle code, hex 7F). The DTCI allows these non-PRI channels to be provisioned as a per-trunk signaling (PTS) trunk. In other words, any AB-trunk supported by DMS-250 switch can be datafilled on the non-PRI channels. D-channel handler to DS-1 mapping There exists a one-to-one mapping between the D-channel handler and the DS-1, as datafilled in table TRKSGRP.

  • Page 236: Optimal Ds-1/D-Channel Handler Card Assignments On Dms-250 Dtci

    11-2 Engineering recommendations Optimal DS-1/D-channel handler card assignments on DMS-250 DTCI This does not apply; this manual pertains to signaling terminal (ST) card provisioning. Signaling terminals This does not apply to the DTCI. DTCI port allocation DS-1/DS-30 port groups For trunk call processing, C-side channels are preallocated for each trunk member.

  • Page 237: Reliability Considerations

    Backup trunk group To reduce the impact of PRI failures or degradations, backup trunk groups can be set up in the DMS-250 switch routing tables. The backup groups can be either PRI or AB-trunk groups. Non-PRI trunks as backup The backup trunk group may reside on the DTCI because it can support non-PRI trunks.
  • Page 238 11-4 Engineering recommendations Table 11-2 Datafill to support the ISDN PRI loss and level plan Key port 1 Key port 2 Data pad 1T02 Data pad 2T01 PRIP PRIP PRIP PONS PRIP POPS PRIP DONS PRIP PRIP PRIP PRIP PRIP PRIP —end—...

  • Page 239: Ds-1 To Ds-30 Channel Mapping

    0/12 1/12 2/12 3/12 0/13 1/13 2/13 3/13 0/14 1/14 2/14 3/14 0/15 1/15 2/15 3/15 0/16 1/16 2/16 3/16 0/17 1/17 2/17 3/17 0/18 1/18 2/18 3/18 0/19 1/19 —continued— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 240 12-2 DS-1 to DS-30 channel mapping Table 12-1 DS-30 port/channel per DS-1 channel and port (continued) DS-1 DS-1 port DS-1 port DS-1 port DS-1 port DS-1 port channel 2/19 3/19 0/20 1/20 2/20 3/20 0/21 1/21 2/21 3/21 0/22 1/22 2/22 3/22 0/23...
  • Page 241 0/19 1/19 2/19 3/19 4/19 0/20 1/20 2/20 3/20 4/20 0/21 1/21 2/21 3/21 4/21 0/22 1/22 2/22 3/22 4/22 0/23 1/23 2/23 3/23 4/23 0/24 1/24 2/24 4/24 4/24 —end— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 243: Etsi Pri

    Institute (ETSI) of the International Telecommunication Union (formerly known as CCITT) ISDN primary rate recommendations for European users. To comply with the deployment of DMS-250 switches in Europe, a new interface was developed. A limited set of features that currently exist on the American National Standards Institute (ANSI) PRI interface is supported for ETSI PRI.

  • Page 244: Protocol-User Mode

    PRI messages and information elements; messages formats Figure 13-1 shows the network mode configuration for ETSI PRI. The DMS-250 is the network side of the ETSI PRI interface and is interworked with ITU ISUP IMT interface to provide communication with the public switched network.

  • Page 245: Parameters

    Unrecognized parameters or parameters for which call processing has not been developed are ignored and discarded. Parameters tandemed across the network will not be processed. The parameter is passed as received from the originating node. Ignored parameters are discarded. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 246: Message Formats

    13-4 ETSI PRI Message formats The following message formats are available: alerting call proceeding connect connect acknowledge disconnect progress release release complete restart restart acknowledge setup setup acknowledge status status enquiry information Protocol timers All protocol timers can be datafilled in table ISDNPROT. Hardware configuration The hardware for the ETSI PRI interface is the DTCOi+ peripheral.

  • Page 247: D-Channel Handler

    ETSI PRI 13-5 The DTCOi+ integrates into the DMS-250 switch in the same manner as the PTDC and is referred to in the switch (for example, at the MAP terminal) as a “PDTC.” The DTCOi+ is similar to the DTCOi except that DTCOi+ uses the single unified processor instead of dual MP/SP processors.

  • Page 248: Identifying Call Type

    Calls originated on ETSI PRI trunks can send the originating site location code (OSLC) and the originating trunk group (OTG) number (both in the SETUP message) to the DMS-250 switch. This occurs by prefixing the OTG and OSLC to the called party number.
  • Page 249 When the first four digits of the called party number and the OSLC digits are received, they are removed from the incoming called party number before pretranslations. The DMS-250 switch does the following with the logical OTG: sends it to the dedicated access point (DAP) as the OTG in a dedicated...

  • Page 250: B-Channel Negotiation

    PRI trunks. If the OSID field is datafilled with a non-NIL value, the logical OTG is expected to be prefixed to the called party number. The DMS-250 uses the value datafilled in the OSID field (the logical OSID) as follows:...
  • Page 251 “Restricted”, the CGN is not delivered. For any other value of PI, CGN is delivered. If CGN is not available and CHG is available, CHG is delivered as CGN with PI of “Allowed” and SI of “Network Provided”. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 252 13-10 ETSI PRI CGNDELV = Secondary CHGDELV = Primary NOATONSC = No CGNPISCR = Yes If CHG is available, CHG is delivered as CGN with PI of “Allowed” and SI of “Network Provided”. Otherwise, if CGN is available, PI of the CGN parameter is screened.

  • Page 253: Ansi Pri

    PI, CHG is delivered as CGN with PI set “Allowed” and SI set to “Network Provided”. If CHG is not available and CGN is available, CGN is delivered. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 254 13-12 ETSI PRI CGNDELV = Always CHGDELV = Never CGNPISCR = Yes If CGN is available, PI of the CGN parameter is screened. If PI is “Restricted”, CGN is not delivered. For any other value of PI, CGN is delivered. If CGN is not available, CGN is not delivered. CGNDELV = Always CHGDELV = Never CGNPISCR = Cond...

  • Page 255: Standard Cause And Treatment Handling

    XPM sends back “Invalid Information identity does not (83) Element Contents” Call identity in use (84) XPM sends back “Invalid Information Element Contents” No call suspended (85) XPM sends back “Invalid Information Element Contents” —continued— Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 256 13-14 ETSI PRI Table 13-1 Cause-to-treatment mapping for ETSI PRI specifications (continued) Cause Treatment Call having the requested call identity XPM sends back “Invalid Information has been cleared (86) Element Contents” Invalid transit network selection (91) Reorder (RODR) —end— Table 13-2 lists the cause values that are mapped differently due to the limitation in the extended peripheral module (XPM).
  • Page 257 111 “Protocol error unspecified” —end— VNET services The VNET services discussed below are available for ETSI PRI. Access to NCS/DAP For ETSI PRI, both dedicated VNET access or shared VNET access is available. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 258 ROUTING RESPONSE—sent by the NCS to the originating switch to indicate successful translation of the VNET call. The information returned is used to route the call to the correct DMS-250 switch and trunk. FAILURE RESPONSE—sent by the NCS to the originating or termination switch to indicate there was some kind of translation failure.

  • Page 259: Remote Access

    After receiving a remote access response or enhanced remote access response, the DMS-250 provides a prompt tone to the subscriber in order to collect digits. The answer supervision enhancement establishes the voice path for DTMF digit collection. The prompt tones required for address and suppcode collection are configurable on each switch.

  • Page 260: In-Band Digit Collection-Answer Supervision

    The DMS-250 sends a CONN message on the originating ETSI PRI trunk under the following conditions: A call originates on a trunk datafilled with the DMS-250 ETSI PRI protocol variant (ETSI250 in table LTDEF).

  • Page 261: Enhanced Overflow

    Enhanced overflow is also supported for Remote Access and Suppcode collections on ETSI PRI trunks. Two existing Application Data Field (ADF) parameters, NO ANSWER TIMER and NCS INFORMATION, are used. If Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 262: Registered Access Calls

    Registered access calls With registered access, a call originating over an ETSI PRI trunk comes into the DMS-250 switch. The switch sends a request to the NCS/DAP for additional routing information or routes the call to an operator. This decision is based on the Nature of Address (NOA) parameter of the calling party number.

  • Page 263: Prism Services

    HNPACONT. A call detail record is generated these calls. subscriber calls national calls For the following calls, translation occurs by means of the universal translation tables. A call detail record is generated these calls. international calls Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 264: Long Call Disconnect

    13-22 ETSI PRI Long call disconnect Calls that remain in an unanswered state are monitored. If the call is unanswered for the period of time specified, the call is disconnected. To use this feature, enable the LCDDUR option for ETSI PRI trunks and specify a period of time in the TRKGRP option.

  • Page 265: In-Switch Account Code Collection

    UUI; it only transports it. This service operates by means of the UUI information element. NCID The DMS-250 switch creates a new network call identifier (NCID) on ETSI PRI originations. Dialable Wideband Service ETSI PRI does not support Dialable Wideband Service.

  • Page 266: Flexcard Call Processing

    13-24 ETSI PRI Variable Number of Card Digits Flexcard call processing All functionality is datafilled in table FLEXSAC. When the access number is datafilled with a PRERTSEL of SAC and a SACFEAT of FLEXFREE or FLEXPREM in table STDPRTCT, the last field, SACATRIDX, provides an index into table SACATTR.

  • Page 267: Flexible Card Type

    If the PRETRANS field is datafilled with the nil value NPRT, the call will generate a Vacant Code (VACT) treatment. This is the same functionality performed by domestic card calls when MCCS_PRTNM is datafilled with NPRT. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 268: Flexible Dialing Stage

    13-26 ETSI PRI Note: Address digit collection is handled in the same manner as the domestic address digit collection for MWC card calls. The only difference is MWC card calls must collect a minimum of 4 digits while the flexible card calls must collect a minimum of only 2 digits and a maximum of 15 digits.

  • Page 269: Variable Number Of Card Digits

    The fields MINDIGS and MAXDIGS in table FLEXSAC are present to determine the number of card digits to collect. These fields should be datafilled to include the pin digit count. For example, to collect a card Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 270: Reorigination

    Reset Digit “#” in collecting Card Digits Reset dialing allows the subscriber to correct a misdialed sequence without losing access to the DMS-250 switch. Dial tone is given upon pressing the reset digit (#) so that the subscriber can redial the digit sequence.

  • Page 271: Routing

    VNET card call. The only exception to this is when Application Data Field (ADF) routing response with action code 32 (EIR no overflow) or 33 (EIR with overflow) is returned from the DAP. This implies that a Private Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 272: Enhanced Overflow

    Enhanced overflow is supported for terminating ETSI PRI interfaces if the ENHANCED_OVERFLOW office parameter is set to “Y” at the originating DMS-250 switch. Enhanced overflow is invoked when the following occurs: A call cannot terminate due to an all trunks busy condition or the trunk receives a release message from an ETSI PRI with a non-normal release cause or no answer timer.

  • Page 273: Etsi Pri Terminations By Way Of Table Oprteid

    Card Call Time-outs. This feature allows ETSI PRI trunks to be datafilled in table OPRTEID for call terminations. None of the other OPNET tables support ETSI PRI trunks. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 275: Ncauui

    DMS-250 switch verifies the subscription of the originating user before further processing the request. After verifying the originating user is subscribed to NCAUUI, the DMS-250 sends an ADF DAL Request message to the DAP based on VNET or FLEXSAC call processing. The DAP validates the ADF DAL request for NCAUUI.

  • Page 276: Non Call Associated User To User Signaling Invocation

    NCAUUI requests. The system rejects the NCAUUI request by way of normal Q.931 setup call processing. In this case, the DMS-250 switch sends a RELease COMPlete message to the originating user in cause values, 65 (Bearer Capability Not Implemented) or 100 (Invalid Information Content Identifier).
  • Page 277 User Information After the Q.931 NCAUUI SETUP message is sent to the terminating user, the DMS-250 switch moves into the Call Received network state (N7) and timer T310 (10 seconds) starts. This timer stops upon receiving the Q.931 CONNect message. If the T310 timer expires before receiving the Q.931 CONNect message, the DMS-250 switch sends a Q.931 RELease COMPlete...

  • Page 278: Ncauui Invocation Rejection

    14-4 NCAUUI The DMS-250 switch does not report the FACility message to the far-end user. Table 14-2 shows the Facility Messages. Figure 14-2 Facility Messages DMS-250 Terminating PBX Originating PBX SETUP (NCAUUI Request) SETUP (NCAUUI Request) FACility w/ CAUUI3 request Facility REJect w/ cause 29 “facility rejected”...

  • Page 279: Network Rejection

    RELease COMPlete RELease COMPlete Network Rejection The DMS-250 rejects an NCA-TSC request with a RELease or RELease COMPlete message. Please refer to Figure 14-4 “NCAUUI Invocation Rejection from Network” for network rejection. When TSC resources are busy, the network rejects the NCA-TSC request.
  • Page 280 “Transit” and coding standard of “CCITT.” If the DMS-250 receives a NCAUUI request in the Q.931 SETUP message for a PRI user that is not subscribed, the DMS-250 switch denies the request by way of the Q.931 RELease COMPlete message with cause value of 50 “Requested Facility Not Subscribed,”...
  • Page 281 Congestion Control message cannot distinguish whether the originator of the message is the far-end user or the DMS-250 switch. When necessary, the DMS-250 switch or the end user controls the transfer of User Information messages by means of a Congestion Control message. The Q.931 Congestion Control message contains a Congestion Level IE that can...

  • Page 282: Network Flow Control

    Level IE set to “Receiver Ready,” the far-end user can resume sending User Information messages to the remote end user. Network Flow Control The DMS-250 switch uses the following algorithm to control the flow of User Information messages: burst parameter X, initialized to office parameter UUS_BURST...

  • Page 283: User Congestion And Network Flow Control Interaction

    DMS-250 only sends a Congestion Control message with “Receiver Ready” to the user previously notified of congestion. User Congestion and Network Flow Control Interaction The DMS-250 switch considers the congestion status of both end users and itself before sending or forwarding Congestion Control messages to the end users.
  • Page 284 User Congestion and Network Flow Control Interaction The DMS-250 switch considers the congestion status of both end users and itself before sending or forwarding Congestion Control messages to the end users.

  • Page 285: Ncauui Tsc Clearing

    User Information NCAUUI TSC Clearing User Clearing Either of the end users utilizes a Q.931 RELease or RELease COMPlete message to clear the NCAUUI connection. The user that receives the Q.931 Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 286: Data Access Point (Dap)

    NCAUUI call. Data Access Point (DAP) All NCAUUI calls must go to the DAP for translation. The DMS-250 switch receives all NCAUUI requests in traditional call requests that invoke VNET or FLEXSAC processing. DAP interaction is necessary to ensure the called party obtains TSID and TTG from the DAP.
  • Page 287 Thus bypassing the IMMDAPREQ field in table STDPRTCT and FLEXSAC tables. If a NCAUUI call is FLEXSAC, but NCS_ALLOW is set to “N” then NCAUUI is rejected. The DMS-250 sends a Q.931 RELease message to the originating user with cause value of 21 “Call Rejected”, location code of ”Transit”, and coding standard of ”CCITT”.
  • Page 288 SETUP message indicating NCAUUI to the terminating PRI user based on the TTG. The subsequent address digits that the switch receives from the DAP at the DMS-250 switch are outpulsed as the Called Party Number IE in the outgoing Q.931 SETUP message.
  • Page 289 NCAUUI request. If the received TSID and the switch ID of the switch that made the DAP request match, the TTG that the DAP receives, the DMS-250 switch uses the value to establish the NCA-TSC. If the TTG referenced in table VPNTRMRT is not an in–service PRI agency, the DMS-250 switch sends a Q.931 RELease COMPlete message with a...

  • Page 291: Ncauui (Two Switch Scenario)

    PRI users that are located on two different switches in the network. The Signaling Connection Control Protocol (SCCP) Class 2 Connection Oriented protocol is used to set up a logical connection between two DMS-250 switch nodes in the CSS7 network without setting up a voice circuit. Once the...
  • Page 292 15-2 NCAUUI When the terminating DMS-250 switch receives an SCCP Class 2 Connection Request (CR) message, it builds and sends the Q.931 SETUP message. The Q.931 message indicates the presence of NCAUUI to the terminating ISDN user based on the TTG received in the SCCP Class 2 CR message.
  • Page 293 A maximum of 2048 SCCP per switch are allowed. An SCCP reference number must be available. Once the terminating DMS-250 switch receives the SCCP CR message, it checks to see if the terminator is a supported ISDN variant. If the system supports the ISDN variant, the DMS-250 switch generates and sends a Q.931 SETUP message to the terminating ISDN user.
  • Page 294 NCAUUI service. Octet 5 is ignored if it is received in a NCAUUI request message. Octets 6 and 7 may be included by the user in NCAUUI requests. However, the DMS-250 switch ignores Octet 6 and Octet 7.

  • Page 295: Connect Timers

    NCA-TSC request message. CAUUI2 and CAUUI3 Requests If the DMS-250 switch receives CAUUI2 requests in the NSF IE included in the Q.931 SETUP message requesting NCAUUI, the DMS-250 switch rejects the CAUUI2 request. The rejection is done by sending a Q.931 FACility REJect message with a cause value of 29 “Facility Rejected”,...
  • Page 296 1 minute. Timer T (connest) is started after the SCCP CR message is sent to the terminating DMS-250 switch. The timer is stopped after it receives the SCCP CC message. The T timer (connest) is available is datafilled in table SCCPTMR.

  • Page 297: Ncauui Invocation Negative Acknowledgment

    18 “no user responding” RELease COMPlete NCAUUI Invocation Negative Acknowledgment User Invocation Rejection The ISDN user at the terminating DMS-250 switch rejects a NCA-TSC request message with a Q.931 DISConnect, RELease or RELease COMPlete Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 298 For example, if the terminating ISDN user negatively acknowledges the request for NCAUUI with the Q.931 DISConnect or RELease message with cause value of 29 “Facility Rejected”, the terminating DMS-250 switch sends a Q.931 RELease COMPlete message to the terminating ISDN user and an SCCP CREF message to the originating switch.
  • Page 299 “facility rejected” RELease COMPlete Network Rejection The DMS-250 switch rejects a NCA-TSC request message with a Q.931 RELease, RELease COMPlete, or SCCP CREF message. Note: A Q.931 RELease Message is sent if NCAUUI rejection occurs at the CC. A Q.931 RELease COMPlete message is sent if NCAUUI rejection occurs at the XPM.
  • Page 300 If the originating DMS-250 switch receives a NCAUUI request in the Q.931 SETUP message from a PRI user that is not subscribed, the request is denied by the DMS-250 switch by way of the Q.931 RELease message with cause value of 50 “Requested Facility Not Subscribed”, location code of “Transit”...
  • Page 301 A maximum of 2048 SCCP per switch are allowed. An SCCP reference number is available. If any one of the above criteria is not met, the originating DMS-250 switch sends a Q.931 RELease with cause value of 21 “Call Rejected” to the originating ISDN user rejecting the NCA-TSC request message.
  • Page 302 UUS extension block If the originating user sends a NCAUUI request in the Q.931 SETUP message and the terminating DMS-250 switch agency is not ISDN PRI or is ISDN PRI that are neither NTMWCPRI or N499PRI variants, the NCAUUI request is rejected. Also, if the originating user sends a NCAUUI request in...
  • Page 303 Q.931 SETUP message and the terminating DMS-250 switch agency is not an in-service PRI agency, the NCAUUI request is rejected. For both cases, the request is denied by the terminating DMS-250 switch by way of the SCCP CREF message. When the originating DMS-250 switch receives the SCCP CREF message, the DMS-250 switch builds and sends a Q.931 RELease message with cause value 21 “Call Rejected”, location code...
  • Page 304 15-14 NCAUUI Figure 15-9 Transfer of User Information Terminating PBX Originating MCI DMS–250 Terminating MCI DMS–250 Originating PBX SETUP (NCAUUI Request) SETUP (NCAUUI Request) Connection Request CONNect CONNect Connection Confirm CONNect ACKnowledge CONNect ACKnowledge User Information DT1 #20 Data Transfer User Information User Information DT1 #20...

  • Page 305: Ncauui Congestion And Flow Controls

    Congestion Control message cannot distinguish whether the originator of the message is the far end user or the DMS-250 switch. When necessary, the DMS-250 switch or the end users control the transfer of User Information messages by means of a Congestion Control message. The Q.931 Congestion Control message contains a Congestion Level IE which is...
  • Page 306 “Receiver Not Ready” indicating congestion or “Receiver Ready” indicating congestion clearing. The Data Parameter field contains a mandatory Cause IE. This cause value is received from the User or generated by the DMS-250 switch. When the far end switch receives an SCCP DT1 message with congestion information, it generates and sends a Q.931 Congestion Control...
  • Page 307 Q.931 Congestion Control message with “Receiver Ready”. Network Flow Control Flow control of User Information messages at the DMS-250 switch is done using the following algorithm: burst parameter X, initialized to office parameter UUS_BURST...
  • Page 308 15-18 NCAUUI N does not exceed X. If the DMS-250 switch, within the period of TUUS timer, receives more than N User Information messages, “network congestion” occurs. The network sends a Q.931 Congestion Control message to the user with Congestion Level IE set to “Receiver Not Ready”...
  • Page 309 Q.931 Congestion Control message with “Receiver Ready” to the access ISDN user because the access DMS-250 switch is still in congestion. Once the network flow control is cleared, the access DMS-250 switch sends the Q.931 Congestion Control message with “Receiver Ready”...
  • Page 310 The office parameter, MAX_USER_INFO, defines the maximum number of User Information (i.e. UUI Information Element) that can be transported for the life of the call. The DMS-250 switch does not check the MAX_USER_INFO for NCAUUI call setup messages (i.e. Q.931 SETUP and Q.931 CONNECT).
  • Page 311 Q.931 RELease COMPlete message. T(connrel) Connection Release Timer T(connrel) timer is the connection release timer where the DMS-250 switch is waiting to receive an SCCP RLC message. The default is 10 seconds. T(connrel) timer is started after the terminating DMS-250 switch sends the SCCP RLSD message to the originating DMS-250 switch.
  • Page 312 15-22 NCAUUI Figure 15-10 NCAUUI and ADF Interaction Terminating PBX Originating PBX Originating MCI DMS–250 SETUP (NCAUUI Request) ADF DAL Request ADF Routing/ Suppcode Response w/ TSID + TTG Terminating MCI DMS–250 SETUP (NCAUUI Request) Connection Request CONNect CONNect Connection Confirm CONNect ACKnowledge CONNect ACKnowledge User Information...
  • Page 313 NCAUUI is only supported for VNET and FLEXSAC call processing. Upon receiving a Q.931 SETUP message indicating NCAUUI request, the DMS-250 switch formulates and sends an ADF DAL Request message to the DAP based on VNET or FLEXSAC call processing. Note that the ADF...
  • Page 314 IMMDAPREQ field in table STDPRTCT and FLEXSAC tables. If a NCAUUI call is a FLEXSAC, but NCS_ALLOW is set to “N” then NCAUUI is rejected. The originating DMS-250 switch sends a Q.931 RELease message to the originating user with cause value of 21 “Call Rejected”, location code of “Transit”, and coding standard of “CCITT”.
  • Page 315 TSID received from the DAP to a routeset for which to establish the TSC. If the TSID is not found in table SCCPDEST, the originating DMS-250 switch sends a Q.931 RELease message with a cause value of 21 Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 316 Before the originating DMS-250 switch generates and sends an SCCP CR message to the terminating DMS-250 switch, the SCCP requirements must be met. If one of the requirements is not met, the originating DMS-250 switch sends a Q.931 RELease with cause value of 21 “Call Rejected” to the originating ISDN user rejecting the NCA-TSC request message.
  • Page 317 DMS-250 switch sends an SCCP CREF message towards the originating switch effectively rejecting the NCAUUI request. Once the terminating DMS-250 switch receives the SCCP CREF message, it builds and sends a Q.931 RELease with a cause value of 21 “Call Rejected” to the originating ISDN user.
  • Page 318 SCCP RLSD message. The terminating DMS-250 switch communicates this cause to the originating user in the corresponding Q.931 RELease message. If the terminating user clears an established NCA-TSC, the DMS-250 switch formulates and sends an SCCP RLSD message towards the originating switch.

  • Page 319: Pri Connected Number Transport

    Connect, Disconnect, Release and Release Complete messages in table ISDNPARM. The DMS-250 switch transports the IE across the network in the corresponding ISUP message by way of the ISUP ATP parameter after receiving the Connected Number IE in one of the following messages: Q.931 Connect...

  • Page 321: Pri Progress Indicator Transport

    The purpose of the progress Indicator is to describe an event that occurs during the life of the call. This feature provides the capability for the MWC DMS-250 switch to transport the progress indicator IE across the CCS7 network by way of the access transport parameter (ATP). The originating MCI DMS-250 converts the location value of the progress indicator.

  • Page 322: 17-2 Pri Progress Indicator Transport

    17-2 Pri Progress Indicator Transport Table 17- Mapping of location in progress indicator at the originating switch Value sent from terminating PRI user Value sent to originating PRI user 2–public network serving the local 4–public network serving the remote user user 3–transit network 3–transit network...
  • Page 323 8–in-band information or an 8–in-band information or an appropriate pattern is now available appropriate pattern is now available Note: This mapping applies to PRI-to-ISUP-to-PRI scenarios. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 324: Processing Scenarios For Backward Call Indicators

    17-4 Pri Progress Indicator Transport Table 17-x Mapping of progress description in progress indicator for ETSIPRI originations Value sent from terminating Value sent to originating PRI user PRI user (ATTPRI, MCIPRI, NAPRI) (ETSIPRI) 1–call is not end-to-end ISDN; 1–call is not end-to-end ISDN; further call progress information may further call progress information may be available in-band...

  • Page 325: Scenario 2: Pri To Isup To Pts

    Note: This scenario does not comply with the ANSI TI.607 standard. Scenario 3: PTS to ISUP to PRI The originator for this scenario is a PTS trunk. This originator interworks with an ISUP trunk, which interworks with a PRI terminator. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 326: Scenario 4: Pri-To-Isup-To-Pri

    17-6 Pri Progress Indicator Transport Table 17- Scenario 3: Parameter field mapping for PTS to ISUP to PRI Calling user/network Network Called user/network ALERTING no mapping applied backward call no progress indicator indicators DC=01 subscriber free I=0 no interworking encountered K=1 uses ISUP end to M=1 terminating access ISDN...

  • Page 327: Scenario 5: Pri-To-Isup-To-Pri

    I=0 no interworking encountered Note: The progress description values of 2, 3, 4, or 8 set the four fields of the backward call indicators of the ISUP ACM message in the same way. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 328: Scenario 6: Pri-To-Isup-To-Isup

    17-8 Pri Progress Indicator Transport Table 17- Scenario 5: Parameter field mapping for PRI-to-ISUP-to-PRI Calling user/network Network Called user/network K=1 uses ISUP end to M=1 terminating access ISDN Note: The progress description values of 2, 3, 4, or 8 set the four fields of the backward call indicators of the ISUP ACM message in the same way.

  • Page 329: Migration Strategy

    Until all switches convert to MCI18, the code for patch BAV40 needs to be active. For MCI18, Nortel Networks will support both the patch and the feature functionality to avoid any migration issues and help prevent the need to convert all switches at once.
  • Page 330 17-10 Pri Progress Indicator Transport This feature does not affect any existing functionality of incoming and outgoing Q.931 PROGRESS messages. Due to the specific functionality of the Q.931 PROGRESS message, the ISDNPARM table cannot control this portion of the feature. You can only turn this feature on if the office parameter ATP_PROGRESS_IND in the OFCOPT table is set to Y.

  • Page 331: Mauui Over Release Message For Ncauui

    Single Switch Scenario NCAUUI for a single switch scenario allows PRI users located on the same MWC DMS-250 to communicate by means of user-to-user signaling without setting up a circuit-switched (bearer/voice channel) connection. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 332 18-2 MAUUI over RELEASE MESSAGE for NCAUUI Backward Clearing Single Switch Scenario 1 The following figure shows how the terminating user releases an NCAUUI call using a Q.931 DISConnect message or a Q.931 RELease message before an NCAUUI call is connected. A UUI request is included in this message and the UUI request is delivered to the originating user.
  • Page 333 SETUP (NCAUUI and MAUUI Request) SETUP (NCAUUI and MAUUI Request) Call Proceeding –––––––––––––––––––– RELease COMPlete (MAUUI) RELease (MAUUI) RELease COMPlete Billing Record should have: TP7Q = 1 UUS_TYPE = 0 UUI_COUNT = 2 Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 334 18-4 MAUUI over RELEASE MESSAGE for NCAUUI Forward Clearing Single Switch Scenario 1 The following figure shows how the originating user clears an NCAUUI call using a Q.931 DISConnect message or a Q.931 RELease message before an NCAUUI call is connected. A UUI request is included in this message and the UUI request is delivered to the terminating user.

  • Page 335: Two Switch Scenario

    For the PRI interface, the user-to-user signaling messages are carried over the D-channel. For the SS7 interface, the user-to-user signaling messages are carried over the SS7 signaling link using SCCP. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 336 Q.931 DISConnect message or a Q.931 RELease message before an NCAUUI call is connected. A UUI request is included in this message and the UUI request is delivered to the originating MWC DMS-250. Figure 18-5 Backward Clearing Two Switch Scenario 1 Terminating PBX Terminating MCI DMS–250...
  • Page 337 NCAUUI call is connected. A UUI request is included in this message, but the UUI request is not delivered to the originating MWC DMS-250. A UUI request is not delivered because the UUI request cannot be accomadated in the data parameter of the SCCP CREF message.
  • Page 338 UUI request because the Data Parameter of the SCCP Connection Request (CR) message cannot accomadate the UUI request. MAUUI service is not activated at the terminating MWC DMS-250. When the terminating user releases the NCAUUI call using a Q.931 DISConnect message or Q.931 RELease message with the UUI request present, the UUI...
  • Page 339 Q.931 DISConnect message or a Q.931 RELease message before an NCAUUI call is connected. A UUI request is included in this message, but the UUI request is not delivered to the terminating MWC DMS-250 switch. The billing field, UUIE_COUNT is not incremented at the originating and terminating switch.
  • Page 340 Q.931 DISConnect message or a Q.931 RELease message before an NCAUUI call is connected. A UUI request is included in the message, but the UUI request is not delivered to the terminating MWC DMS-250, and the billing field, UUIE_COUNT, is not incremented for this message.
  • Page 341 NCAUUI call by way of a Q.931 DISConnect message or a Q.931 RELease message before an NCAUUI call is connected. A UUI request is included in the message, but it is not delivered to the terminating MWC DMS-250. The billing field, UUIE_COUNT, is not incremented for this message.
  • Page 342 18-12 MAUUI over RELEASE MESSAGE for NCAUUI Billing Billing utilizes the existing NCAUUI fields and procedures implemented in MCI15. The only exception to this is setting the TP7Q field before the Q.931 CONNect. TP7Q is set to 1 if TSC is released by the called party and set to 0 if TSC is cleared by the calling party.

  • Page 343: Mauui In First Call Clearing Message Before Connect

    The first call clearing message from the terminating agent is received before the terminating agent answers the call or the originating agent receives an answer indication (i.e. An ISUP ANM or Q.931 Connect). Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 344: Feature Description

    19-2 MAUUI MAUUI is invoked on a call by way of the call setup message in order for any other call control messages to contain UUI for transport. If UUI is not sent in the call setup message, the UUI received in any other call control messages is discarded.

  • Page 345: Pri-Pri Scenarios

    Q.931 Setup message to invoke the MAUUI service. The Q.931 Setup message with UUI is sent to the terminating PRI agent. The terminating PRI agent responds to this message with a Q.931 DISConnect message with Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 346 The following diagram shows the PRI to PRI call clearing before alerting without treatment applied. Figure 19-1 PRI-PRI Call Clearing before Alerting when Treatment not Applied MWC DMS-250 Q.931 Setup (UUI) Q.931 Setup (UUI) Q.931 Call Proceeding Q.931 Call Proceeding Q.931 DISConnect (UUI)
  • Page 347 UUI. If treatment is not to be applied at this switch, the UUI is transported to the originating PRI agent in the corresponding Q.931 DISConnect message. The following diagram shows the PRI to PRI call clearing before connect when treatment is not applied. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 348 19-6 MAUUI Figure 19-3 PRI–PRI Call Clearing before Connect when Treatment not Applied MWC DMS-250 Q.931 Setup (UUI) Q.931 Setup (UUI) Q.931 Call Proceeding Q.931 Call Proceeding Q.931 Alerting (UUI) Q.931 Alerting (UUI) Q.931 DISConnect (UUI) Q.931 DISConnect (UUI) Q.931 RELease Q.931 RELease...

  • Page 349: Isup-Isup Scenarios

    Address Completed Message (ACM) when treatment not applied” scenario. Figure 19-5 ISUP–ISUP Call Clearing before ACM when Treatment not Applied MWC DMS-250 ISUP IAM (UUI) ISUP IAM (UUI) ISUP REL (UUI) ISUP REL (UUI) ISUP RLC ISUP RLC Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 350 The following diagram shows the “ISUP to ISUP clearing before ACM when treatment applied” scenario. Figure 19-6 ISUP–ISUP Call Clearing before ACM when Treatment Applied MWC DMS-250 ISUP IAM (UUI) ISUP IAM (UUI) ISUP ACM (UUI) ISUP REL (UUI)

  • Page 351: Pri-Isup/Isup-Pri Interworking Scenarios

    In the first scenario, the originating PRI agent includes UUI in the Q.931 Setup message to invoke the MAUUI service. An ISUP IAM message with UUI is sent to the terminating ISUP agent. The terminating ISUP agent Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 352 The following diagram show the “PRI to ISUP call clearing before ACM when treatment is not applied” scenario. Figure 19-9xxx PRI–ISUP Call Clearing before ACM when Treatment not Applied MWC DMS-250 Q.931 Setup (UUI) ISUP IAM (UUI) Q.931 Call Proceeding Q.931 DISConnect (UUI) ISUP REL (UUI) Q.931 RELease...
  • Page 353 UUI. If treatment is not applied at this switch, the UUI is transported to the originating PRI agent in the corresponding Q.931 DISConnect message. The following diagram shows the “PRI to ISUP call clearing before ANM when treatment is not applied” scenario. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 354 19-12 MAUUI Figure 19-11 PRI-ISUP Call Clearing before ANM when Treatment not Applied MWC DMS-250 Q.931 Setup (UUI) ISUP IAM (UUI) Q.931 Call Proceeding Q.931 Alerting (UUI) ISUP ACM (UUI) Q.931 DISConnect (UUI) ISUP REL (UUI) Q.931 RELease ISUP RLC Q.931 RELease COMPlete...
  • Page 355 ISUP agent before the treatment is applied. The following diagram shows the “ISUP to PRI call clearing before alerting when treatment is applied” scenario. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 356 19-14 MAUUI Figure 19-14 ISUP-PRI Call Clearing before Alerting when Treatment Applied MWC DMS-250 Q.931 Setup (UUI) ISUP IAM (UUI) Q.931 Call Proceeding ISUP ACM (UUI) Q.931 DISConnect (UUI) Applied tones or announcements Q.931 RELease ISUP REL Q.931 RELease COMPlete...

  • Page 357: Network Scenarios

    Q.931 RELease Applied tones or announcements Q.931 RELease COMPlete ISUP REL ISUP RLC Network Scenarios This section concentrates on multiple switch scenarios where the terminating switch applies tones/announcements to the originating agent. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 358 Q.931 Alerting message is because the interworking bit in the Backward Call Indicator of the ACM denotes that interworking was encountered.) Figure 19-17 PRI-ISUP-PRI Call Clearing Received before Alerting when Treatment Applied MWC DMS-250 MWC DMS-250 Q.931 Setup (UUI) ISUP IAM (UUI) Q.931 Setup (UUI) Q.931 Call Proceeding...

  • Page 359: Special Cases

    ETSI PRI trunks and concentrate on the interworking of these features with respect to ISUP RSLR OPT2 and ISUP IMT originating agents. The following diagram shows an example of the message flow of a call with ASE active. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 360 19-18 MAUUI Figure 19-19 ASE Messaging Flow MWC DMS-250 ISUP RSLR OPT2 MCI ISDN PRI ISUP IAM ASE_ACTIVE ISUP ACM ISUP ANM Digit Collection Q.931 Setup Q.931 Call Proceeding Q.931 Alerting Q.931 Connect Q.931 DISConnect ISUP REL Q.931 RELease ISUP RLC Q.931 RELease COMPlete...
  • Page 361 Suppcode Collection/Digit Collection Suppcode/Digit Collection is allowed if card or address digits are to be collected from the originating agent. In this case, the DMS-250 switch sends out an ACM to the originating agent to establish voice path for digit collection.
  • Page 362 19-20 MAUUI Figure 19-21 Suppcode/Digit Collection Example MWC DMS-250 ISUP RSLR OPT2 MCI ISDN PRI ISUP IAM ISUP ACM Digit Collection Q.931 Setup Q.931 Call Proceeding Q.931 Alerting Q.931 Connect Q.931 DISConnect ISUP REL Q.931 RELease ISUP RLC Q.931 RELease COMPlete...

  • Page 363: Etsi Pri

    Since ETSI PRI agents do not support the UUI IE in the Q.931 PROGress message, ETSI PRI agents do not receive UUI if tones/announcements are applied and UUI is received from the terminator in a call clearing message. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 364: Billing

    19-22 MAUUI Figure 19-23 ETSI PRI Functionality MWC DMS-250 ETSI PRI ISUP/PRI Q.931 Setup (UUI) CallSsetup Message (UUI) Q.931 Call Proceeding Applied tones or announcements Call Clearing Message (UUI) Q.931 DISConnect Q.931 RELease Q.931 RELease COMPlete In the sceanrios where tones/announcements are not applied at the switch...
  • Page 365 MAUUI 19-23 is cleared by the called party before an answer is received to indicate the called party disconnected the call. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)

  • Page 367: List Of Terms

    Condition indicated when all the circuits in a group are occupied. See automatic message accounting. See automatic number identification. Answer Message ANSI American National Standards Institute See audio response unit. ASEQ ascending sequence Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 368 20-2 List of terms See all trunks busy. See audio tone detector. Access Transport Parameter automatic trunk routing See automatic trunk testing. audio response unit Provides functions as a part of Enhanced Voice Services that include menu routing, announcements, and voice mail. The ARU can record and replay audio messages and detect customer DTMF digits or voice inputs.
  • Page 369 In data transmission, a supplementary service provided by the network that allows a terminating party to be notified of the network address of the originator. Screening of calling line identification is performed during call setup only. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 370 20-4 List of terms calling party identification Record indicating information about the originating party. Call Associated CAUUI Call Associated User to User Information CAMA See centralized automatic message accounting. central controller See call condense block. CCS7 See Common Channel Signaling 7. CCITT International Telephone and Telegraph Consultative Committee;...
  • Page 371 See call processing busy. See customer premises equipment. See calling party identification. cyclic redundancy check Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 372 DIGMAN digit manipulation digital recorded announcement machine A peripheral module developed for the DMS-250 switch. Voice messages are stored in digital form to provide access to up to 30 different service voice announcements. 297-2521-106 Standard 23.01 March 2001...
  • Page 373 Northern Telecom digital systems. The DS-1 signal carries 24 information channels with 64 kbit/s for each channel (DS-0). digital signal 30 A link used internally in the DMS-250 switch. DS 30 handles a data rate of 2.54 mbit/s. direct distance dialing A telephone exchange service that permits subscribers to call a number outside their local area without operator assistance.
  • Page 374 20-8 List of terms DTCI See ISDN digital trunk controller. DTMF See dual tone multifrequency signaling. direct termination overflow dual-tone multifrequency signaling A signaling method that uses set combinations of two specific voice-band frequencies, one of which is selected from a group of four low frequencies, and the other from a group of three or four relatively high frequencies.
  • Page 375 (formerly known as CCITT) ISDN primary rate recommendations for European users. The ETSI PRI interface functions solely as a point of connection between the DMS-250 switch, the PBX, and a remote point of presence. See Enhanced Voice Services and audio response unit.
  • Page 376 20-10 List of terms HDLC high-level data link control HNPA home numbering plan area 6x64 - 384 kbit/s 24x64 - 1536 kbit/s See Initial Address Message. IDDD international direct-distance dialing idle See information element. See interexchange carrier. interface identifier intermachine trunk installation busy information element Information elements (also called parameters) are contained in signaling...
  • Page 377 ISDN network services. The ISUP provides the functionality in a CCS7 network for voice and data services. International Standards Organization ISDN signaling processor ISTB in service trouble Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 378 20-12 List of terms ISUP See ISDN user part. integrated trunk access information transfer rate ITU–T International Telecommunication Union–Telecommunication Standardization Sector LAPB See link access procedure on the B-channel. LAPD See link access procedure on the D-channel. LCGA local carrier group alarm line trunk controller Peripheral module that combines the line group controller and the digital trunk controller and provides all of the services offered by both.
  • Page 379 NACK not acknowledged NARS Network audio response system. See Enhanced Voice Services. NCAUUI Non–Call Associated User–to–User Information NCAUUS Non_call Associated User–to–User Service See network control system. NCTE network customer terminating equipment Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 380 MWC. Specified operations are downloaded to this remote database. This downloading decreases the amount of information stored within the DMS-250 switch, increases the number of customers allowed to access the network, and increases the flexibility and speed of the switch.
  • Page 381 Protocols may govern portions of a network, types of service, or administrative procedures. per-trunk signaling Q.921 CCITT recommendation for layer 2 of ISDN; protocol used to carry signals on D-channels of ISDN access interfaces Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 382 Reset dialing allows the subscriber to correct a misdialed sequence without losing access to the DMS-250 switch. Dial tone is given upon pressing the reset digit (#) so that the subscriber can redial the digit sequence. release link trunk RPOP See remote point of presence.
  • Page 383 A three-digit code (000–999) that allows the DMS-250 switch to separate its customers into unique partitions. STS codes are used in the routing tables of the switch for translations. Every call that enters the DMS-250 switch is assigned an STS;...
  • Page 384 20-18 List of terms severe errored seconds SETUP Q.931 message type superframe format super generic digits signaling system 7 A dual processor device with an 8085-based master processor and an 8031-based data link processor resident in a single card in the message switch and buffer 7 frame.
  • Page 385 TCAP provides the ability for the service switching point (SSP). TCAP is used by the ISDN layer facility message to transport service information for transaction signaling (not associated with an active call) over PRI links. Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 386 A call terminates in a specified treatement code either because the translations supplied by the operating company lead the call to a specified treatment or because the DMS-250 switch detects certain conditions and prescribes a treatment code without reference to operating company translations.
  • Page 387 XMS peripheral module An XPM has two processors in a hot-standby configuration: a master processor and a signaling processor. See XMS peripheral module. zero code suppression Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
  • Page 388 20-22 List of terms 64 kbit/s restricted 64 kbit/s clear (unrestricted) 297-2521-106 Standard 23.01 March 2001...
  • Page 390 Except as expressly authorized in writing by Nortel Networks, the holder is granted no rights to use the information contained herein. Information is subject to change without notice. Nortel...

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