Precedence Ring Tone; Detecting Collect Calls; Advice Of Charge Services For Euro Isdn - AudioCodes Mediant 3000 User Manual

b.
c.
•
The softswitch performs a network preemption of an outbound call request for the
device that has not received a SIP 2xx response - the following sequence of
events occur:
a.
b.

27.6.2 Precedence Ring Tone

You can configure the duration for which the device plays a preemption tone to the Tel and
IP sides if a call is preempted, using the PreemptionToneDuration parameter.
27.7

Detecting Collect Calls

The device detects collect calls (reverse charge calls) using any of the following
information elements (IE) in the received Q.931 ISDN Setup message for Tel-to-IP calls:

Reverse Charging Indication IE

Facility IE
When the device detects a collect call, it adds a proprietary header (X-Siemens-Call-Type:
collect call) to the outgoing SIP INVITE message.
This support does not require any configuration and is applicable to the Euro ISDN protocol
variant.
27.8

Advice of Charge Services for Euro ISDN

Advice of charge (AOC) is a pre-billing function that tasks the rating engine with calculating
the cost of using a service and relaying that information back to the customer (caller). This
allows users to obtain call charging information periodically - during the call (AOC-D) and at
the end of the call (AOC-E).
The AOC messages are sent in the EURO ISDN Facility Information Element (IE)
message. The device interworks these ISDN messages with SIP by converting the AOC
messages into SIP INFO (during call) and BYE messages (end of call), using AudioCodes
proprietary SIP AOC header, and vice versa. The device supports both currency (monetary
units) and pulse (non-monetary units) AOC messages.
This feature can typically be implemented in the hotel industry, where external calls made
by guests can be billed accurately. In such a setup, the device is connected on one side to
a PBX through an ISDN line (Euro ISDN), and on the other side to a SIP trunk provided by
an ITSP. When a call is made by a guest, the device first sends an AOC-D Facility
message to the PBX indicating the connection charge unit, and then sends subsequent
AOC-D messages every user-defined interval to indicate the charge unit during the call.
When the call ends, the device sends an AOC-E Facility message to the PBX indicating the
total number of charged units.
User's Manual
The device initiates the release procedures for the B-channel associated
with the call request and maps the preemption cause to PRI Cause = #8
'Preemption'. This value indicates that the call is being preempted. For PRI,
it also indicates that the B-channel is not reserved for reuse.
The device sends a SIP 200 OK in response to the received BYE, before the
SIP end instrument can proceed with the higher precedence call.
The softswitch sends the device a SIP 488 (Not Acceptable Here) response
code with this Reason cause code. The device initiates the release
procedures for the B-channel associated with the call request and maps the
preemption cause to PRI Cause = #8 'Preemption'.
The device deactivates any user signaling (e.g., ringback tone) and when
the call is terminated, it sends a SIP ACK message to the softswitch.
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Mediant 3000
Document #: LTRT-89738