Avaya 03-300430 User Manual

ATM-BCH explains how to test and repair TN230x ATM Interface circuit packs (TN2305 and 
TN2306) that have ATM B-channel trunks administered for ATM Circuit Emulation Service 
(CES).
For additional repair information, see also 

on page 522, 

on page 598 and 

For maintenance instructions for TN230x circuit packs that are administered as Expansion 
Interfaces for ATM network connectivity, see 

Under ATM Circuit Emulation Service, you simulate ISDN-PRI circuits by assigning ATM ports 
to signaling groups.  Each signaling group represents a PRI circuit, and the ports in the group 
represent the D channel and B channels of that circuit.  B channels must also be assigned to 
ISDN-PRI trunk groups.  TN230x circuit packs support up to 248 ports per circuit pack.

B (bearer) channels (ATM-BCH) transmit digitized voice or data, while a separate D channel 
(ATM-DCH) handles call-control signaling.  One D channel handles signaling for a group of B 
channels that combine to form a signaling group (ATM-SGRP).

ATM-BCH

MAJ

1

1. A MAJOR alarm on a trunk means that alarms on these trunks are not downgraded by 

set options, and at least 75% of the trunks in this trunk group are alarmed.

test port location l

ATM B-Channel Trunk

ATM-BCH

MIN

test port location l

ATM B-Channel Trunk

ATM-BCH

WRN

test port location sh

ATM B-Channel Trunk