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DEFINITY Enterprise Communications Server Release 6
Maintenance for R6vs/si
555-230-127
Issue 1
August 1997
Reliability Systems: A Maintenance Aid
Page 6-4Duplicated Hardware
6
Duplicated Hardware
A description of the hardware components used in a high or critical reliability
system follows.
SPE Duplication
Each SPE in a high or critical reliability system consists of the following circuit
packs:
■ Processor Circuit Pack (TN790)
■ Network Control Circuit Pack (TN777B)
■ Packet Control Circuit Pack (TN778)
NOTE:
There may be zero or one Packet Control circuit pack. However,
both SPEs must have an equal number of circuit packs.
■ Processor Interface Circuit Pack(s) (TN765)
NOTE:
There may be zero, one, or two Processor Interface circuit pack.
However, both SPEs must have an equal number of Processor
Interface circuit packs.
■ Duplication Interface Circuit Pack (TN772)
Duplication Interface Circuit Pack
The Duplication Interface circuit pack is required to support SPE duplication.
Duplication Interface A is part of the SPE in the A control carrier, and Duplication
Interface B is part of the SPE in the B control carrier.
The Duplication Interface circuit packs provide a broad range of functionality.
Alone, Duplication Interface A provides control of the following components: the
duplicated Processor circuit packs, the duplicated Tone-Clock circuit packs, the
environmental maintenance monitoring and control, and G3MT terminal
connection. Together, Duplication Interface A and Duplication Interface B
provide memory shadowing from Active SPE Memory to Standby SPE Memory
and communication between software on the Active SPE and the Standby SPE.
Duplication Interface A controls a lead that indicates to the duplicated Processor
and Network Control circuit packs, respectively, which SPE is currently the Active
SPE. This lead is known as the SPE Select lead. Duplication Interface A controls
another set of leads that indicate to the duplicated TN768 and TN780 8