DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Object Repair Procedures
9-148ATM-BCH (ATM B-Channel Trunk)
9
ATM-BCH (ATM B-Channel Trunk)
This maintenance object expl ains how you 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 maintenance instructions for TN230x circ uit packs that are adm inistered as
Expansion Interfaces for ATM network connectivity, see the ‘‘ATM-EI (Expansion
Interface Circuit Pack)’’ maintenanc e object.

ATM Circuit Emulation Service

Under ATM Circuit Emulation Service, you simulate ISDN-PRI circuits by
assigning ATM ports to

signaling groups

. Each signaling group rep resents a PRI
circuit, and the por ts in the group represent the D-channe l and B-channels of that
circuit. B-channels must also b e assigned to ISDN-PRI trunk groups. TN230x
circuit packs support up to 248 ports per circuit pack.

Signaling group components

Bearer (B) channels (ATM-BCH) transmit digitized voic e or data, while a separate
D-channel (ATM-DCH) handles call-control sig naling. One D-channel hand les
signaling for a group of B-channels that comb ine to form a signaling g roup
(ATM-SGRP).

B-channel service states

The ISDN specification defines 2 servic e state categories for B-c hannels as
listed in Table 9-61.
MO Name (in
Alarm Log) Alarm Level Initial Command to
Run1
1. UU is the universal cabinet number (1 for PPN, 2-44 for EPNs). C is the carrier designation (A, B,
C, D, or E). SS is the number of the slot where the circuit pac k resides (01-21). ppp is the 3-digit
port number (9-256).
Full Name of MO
ATM-BCH2
2. For additional repair information, see also ‘‘ATM-DCH (ATM D-Channel Port)’’, ‘‘ATM-SGRP (ATM
Signaling Group)’’ and PKT-B US.
MAJOR3
3. A MAJOR alarm on a trunk means that alarms on these trunks are not downgraded by the set
options command, and at least 75% of the trunks in this trunk group are alarmed.
test port UUCSSppp l ATM B-Channel Trunk
ATM-BCH MINOR test port UUCSSppp l ATM B-Channel Trunk
ATM-BCH WARNING test port UUCSSppp sh ATM B-Channel Trunk