DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Object Repair Procedures
9-1178PE-BCHL (PRI Endpoint Port)
9
■Use standard ISDN-PRI signaling
■Adhere to the administered PRI endpoi nt boundaries when initiating calls
■Handle incoming c alls appropriately, based on the originating PRI
endpoint
Signaling and B-Channel States
PRI ports use a separate channel call ed the D-channel for call c ontrol and
signaling messages. This is c alled out-of-band signaling. The D-channel
associated with the set of B-c hannels is an ISDN-PRI signaling link port
(ISDN-LNK). The signaling protocol used on the ISDN-PRI signaling link port
D-channel is defined b y one of the four selectable ISDN-PRI Specification s:
Lucent, CCITT, ECMA, and ANSI.
The ISDN-PRI Specification defines the possible servic e states for a B-channel.
The service state is negotiated with the far- end terminal adapter, c hanges over
time, and can have a far-end and near-end comp onents. The service state is
initialized to Out-Of-Service/Far-End, and an attemp t is made to negotiate it to
In-Service. The service state of a partic ular PRI endpoint port B-channel c an be
displayed with the status pri-endpoint extensi on command.
If a call is present, the Specific ation defines the permi ssible call statES as well.
There are tests in the short and long test sequenc es for the PRI endpoint port
designed to aud it these states and ensure agreement b etween both ends of the
PRI wideband connection.
Alarming Based on Service States
A PRI endpoint port B-channel log s a warning alarm when it is p laced in a
Maintenance/Far-End or Out-Of-Service/Far-End state. While in such a state, the
port is unusable for c alls to the terminal adapter. However, t he user can still use
the other remaining ports in the PRI endpoint t o make calls to and from the
terminal adapter. When a warning alarm is raised, use the status pri-endpoint
extension command to deter mine the exact state of the port. Ot her alarms can
be diagnosed by using the short and long test sequences . Note that a PRI
endpoint port B-c hannel can be p laced in a far-end service state by d irect action
by the far-end terminal adap ter or by inaction of the far-end terminal adapter. For
example, if it does not respond to a Remote Layer 3 Query (see Test #260 for
ISDN-LNK) the associated PRI endpoint por t B-channels will be pla ced in the
Maintenance/Far-End service state.
A PRI endpoint port is a port on a UD S1 interface circuit pac k and thus dep ends
on the health of the circuit pac k for proper operati on (see the following figure). A
problem on the associated ISDN-PRI Signaling Link Port D-channel (ISDN-LNK)
can also affect the PRI endpoint. The ISDN-PRI Signaling Link Port in turn
dep ends on th e SYS-LIN K (Sys tem Li nk) to the Pa cket Inter fac e. Ke ep th is
hierarchy of depend encies in mind when d iagnosing prob lems.