Nortel DMS-100 Series Maintenance Manual page 46

1-30 Maintenance overview
The UP receives a start or stop ringing message from the TPT. After the UP
receives a message, the UP ringing task sends messages to the A/B-bit
facility. The A/B-bit facility sends the required A- and B-bits on the correct
P-side channel. This process generates a ringing pattern. The A/B-DDL
message card sends the signaling bits. The A/B-bit facility scans the P-side
channel for signaling patterns that indicate a subscriber answered the
telephone. When the A/B-bit facility detects an answer, the facility sends a
confirmation message to the UP ringing task.
In Mode II, hook state for subscriber lines transmits in the C-field as an
activity message. The message moves from the RCS to the DDL facility.
The SMS maintenance software module
The SMS maintenance software makes sure that the SMS-RCS subsystem
performs accurately. When operating company personnel issue the busy
(BSY), return to service (RTS), or test (TST) commands at the MAP
terminal, the CM transmits messages. The CC sends associated messages to
SMS maintenance software. The SMS maintenance software processes CM
messages that request open or close SMS P-side ports. If errors occur, SMS
maintenance software informs the CM.
The SMS maintenance software performs the following tasks:
The SMS maintenance software allows the operating company personnel to
protect switch protection lines manually.
The following sections describe the system setup required for call
processing. These sections describe the sequence of events that occurs
during call processing.
Call processing setup
Call processing requires the following setup:
297-8231-550 Standard 09.01 August 1998
transmission of RCS alarm information to the CM
activation of channel and loop tests
update of data tables
The UP maintenance software loads static data tables
The UP maintenance software to opens configured SMS P-side ports
because of a CM request. The UP maintenance software closes ports
that remain
The UP maintenance software allows external signaling for all channels
on opened P-side ports. This condition allows the A/B-bit facility to
transmit the required A-bits and B-bits on the channels.