DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Object Repair Procedures
9-956ISDN-TRK (DS1 ISDN Trunk)
9
On 24-channel interfaces, any of the f irst 23 ports on the DS1 circuit p acks can
be a B-channel. On the TN464C/D UDS1 circuit p ack, the 24th port may b e used
as a B-channel or as a D-channel d epending on the typ e of ISDN-PRI signaling
group (FAS or NFAS) implemented on the circuit pack. For more details, refer to
‘‘ISDN-SGR (ISDN-PRI Signaling Group)’’P in this chapter. On the TN767 DS1
circuit pack, all 24 p orts are used as B-channels sinc e D-channel signaling is not
supported on the TN767 c ircuit pack. The signal ing for these B-channels is d one
over a D-channel located on a UDS1 TN464C/D board.
On 32 channel interfaces, any of p orts 1-15 and 17-31 on the DS1 interface
circuit pack c an be a B-channel. The 16th p ort may be used as a B-c hannel or as
a D-channel depend ing on the type of ISDN-PRI signaling group (FAS or NFAS)
to which it belongs. For more deta ils, refer to ‘‘ISDN-SGR (ISDN-PRI Signaling
Group)’’ and "DS1-BD (DS1 Interface Circuit Pack)" in this chapter.
For interfaces using country p rotocol 1 on the DS1 circuit pac k administration
form (including US), the sig naling protocol used for the maintenance of the
B-channel is defined b y the Lucent ISDN-PRI specification. For interfac es using
country protocols other tha n 1, the signaling protoc ol used for the maintenance
of the B-channel is defined by the CCITT ISDN-PRI Specification.
There are five possible service states for a B- channel. the service state is
negotiated with the far-end sw itch, changes over tim e, and may have a far-end
and near-end comp onents. The service state is initialized to
out-of-service/Far-End and an attempt is mad e to negotiate it to in-service.
The Lucent ISDN-PRI Specification defines the possib le SERVICE STATES for a
B-channel. The service state is negotiated with the far-end switch, c hanges over
time, and may have a far-end or near-end component. The service state is
initialized to the Out-Of-Service/Far-End state and an atte mpt is made to
negotiate it to In-Service.
NOTE:
The service state of a particular DS1 ISDN Trunk B-channel can b e
displayed by issuing the status trunk

trunk group/trunk member

system
technician command.
When a call is present, the spec ification defines the per missible call states as
well. There are tests in the short and long test seque nces for DS1 ISDN Trunk
designed to aud it these states and ensure agreement b etween both ends of the
PRI connection.
Alarming Based on Service States
A warning alarm is logg ed against a DS1 ISDN B-channel trunk when it is p laced
in the Maintenance/Far-End or Out-Of-Service/Far-End states, during which the
trunk is unusable for outgoing calls. When a warning alarm is p resent, use status
trunk group#/member# com mand to determine the exac t state. Other alarms
can be diag nosed by using the shor t and/or long test seque nces. Note that an