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 endpoint boundaries when initiating calls
■ Handle incoming calls appropriately, based on the originating PRI
endpoint
Signaling and B-Channel States
PRI ports use a separate channel called the D-channel for call control and
signaling messages. This is called out-of-band signaling. The D-channel
associated with the set of B-channels is an ISDN-PRI signaling link port
(ISDN-LNK). The signaling protocol used on the ISDN-PRI signaling link port
D-channel is defined by one of the four selectable ISDN-PRI Specifications:
Lucent, CCITT, ECMA, and ANSI.
The ISDN-PRI Specification defines the possible service states for a B-channel.
The service state is negotiated with the far-end terminal adapter, changes over
time, and can have a far-end and near-end components. The service state is
initialized to Out-Of-Service/Far-End, and an attempt is made to negotiate it to
In-Service. The service state of a particular PRI endpoint port B-channel can be
displayed with the
status pri-endpoint
extension command.
If a call is present, the Specification defines the permissible call statES as well.
There are tests in the short and long test sequences for the PRI endpoint port
designed to audit these states and ensure agreement between both ends of the
PRI wideband connection.
Alarming Based on Service States
A PRI endpoint port B-channel logs a warning alarm when it is placed in a
Maintenance/Far-End or Out-Of-Service/Far-End state. While in such a state, the
port is unusable for calls to the terminal adapter. However, the user can still use
the other remaining ports in the PRI endpoint to make calls to and from the
terminal adapter. When a warning alarm is raised, use the
status pri-endpoint
extension command to determine the exact state of the port. Other alarms can
be diagnosed by using the short and long test sequences. Note that a PRI
endpoint port B-channel can be placed in a far-end service state by direct action
by the far-end terminal adapter 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 port B-channels will be placed in the
Maintenance/Far-End service state.
A PRI endpoint port is a port on a UDS1 interface circuit pack and thus depends
on the health of the circuit pack for proper operation (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
depends on the SYS-LINK (System Link) to the Packet Interface. Keep this
hierarchy of dependencies in mind when diagnosing problems.
