DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Alarms, Errors, and Troubleshooting
5-83Packet Bus Fault Isolation and Repair
5
■TN464F Universal DS1 circuit pack [UDS1-BD, ISDN-LNK] supports
ISDN-PRI communications over an attached DS1 facility. It transports of
D-channel signaling infor mation over the packet bus , and B-channel data
over the TDM bus. The Universal DS1 circuit pack has the same fault
detection cap abilities as the TN570 Expansion Interface.
■TN771D Maintenance/Test circuit pack [M/T-BD, M/T-DIG, M/T-PKT,
M/T-ANL] is the workhorse of packet b us maintenance. This circuit p ack
can detect all p acket bus failures for the Port Network in whic h it resides.
In Critical Reliability systems (dup licated PNC), this circui t pack enables
the reconfiguring of the p acket bus around a small numb er of failed leads.
The TN771D circuit pack provid es a standalone mode (one that d oes not
involve communication with the SPE), for inspecting the packet bus for
faults. Standalone mode is a critic al tool for troubleshooting p acket bus
faults.
NOTE:
All Maintenance/Test circuit packs must b e of vintage TN771D or
later. This circuit pack is also used for ISDN-PRI trunk testing
(M/T-DIG) and ATMS trunk testing (M/T-ANL).
Effects of Circuit Pack Failures on the Packet Bus
Certain failures of any of the above circuit p acks can disrup t traffic on the packet
bus Some failures cause packet bus failures with correspond ing alarms, while
others cause service outag es without alarming the pac ket bus, (although the
failed circuit pac k should be alarmed ).
Packet bus circuit p ack failures affect the bus in the fo llowing ways:
■TN1655 Packet Interface. A failure of the Packet Interface typ ically
causes all Packet traffic in the system to fail . As a result,
— Exp ansion Port Networks and Center Stage Switches are disab led.
— ISDN-BRI sets are not able to ma ke or receive calls.
— C ommunication with ASAI adjuncts fail
— X.25 c ommunications with external adjunc ts fail.
— System Ports are d isabled.
— ISDN-PRI D-channel sig naling is disabled .
If the failure is on the packet bu s interface, the packe t bus may be
alarmed as well.
In a sy stem with d upl ica ted SPEs , ther e is o ne TN16 55 Pac ket I nterf ace in
each SPE. If a Pa cke t Inte rfac e fail ure in the a ctiv e SPE cau ses a p ac ket
bus d isru ptio n, an SPE interc han ge ma y rest ore se rvic e. In other case s,
replacement of the circ uit pack may be req uired before service is
restored.