Avaya Definity SI, Maintenance Manual, Page: 762 / 2968

Packet Bus Fault Isolation and Correction
555-233-123 9-10 Issue 4 May 2002
Overview of Fault Correction Procedures
This section gives an overview of the procedures used to (1) isolate the cause of
Packet Bus faults and to (2) correct the Packet Bus faults. These procedures are
applicable to High and Critical Reliability systems, and they are detailed fully later
in this chapter:
1. The first procedure attempts to determine if a circuit pack that interfaces to
the Packet Bus is the cause of the Packet Bus problem. The error and
alarm logs are examined for entries for these circuit packs, and the normal
maintenance procedures for those circuit packs are attempted.
2. If the Packet Bus problem still exists, port circuit packs (those in the purple
slots) are removed to look for circuit pack(s) that have failed and/or have
damaged the Packet Bus pins (a diagram of the backplane pins is provided
later).
3. If the Packet Bus problem is still not resolved, the same procedure is
attempted for the control complex circuit packs.
4. If the problem is still not resolved, or if the Packet Bus faults are known to
have open leads, a procedure is undertaken in which the bus terminators
and cables are replaced. If this does not resolve the problem, the carrier
connectivity of the port network is reconfigured to attempt to isolate a faulty
carrier.
The Maintenance/Test Circuit Pack
(TN771D)
Description
Packet bus reconfiguration is available only in high and critical reliability systems.
In such systems that use the packet bus, a Maintenance/Test is required in each
port network. In other configurations (for example, Standard Systems, no packet
bus use), the circuit pack is optional.
!
CAUTION:
All TN771 circuit packs must be of TN771D vintage or later.
Normal Packet Functionality
The Maintenance/Test Packet Bus Port provides the packet bus testing and
reconfiguration capabilities. When the port is in service, the port continuously
monitors the packet bus for faults (or recovery from faults), and it reports this
information to packet bus maintenance.