DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126
Issue 4
June 1999
Maintenance Architecture
1-16SPE Duplication
1
SPE Duplication
The Switch Processing Element (SPE) consists of the following circuit packs.
These circuit packs reside on the A carrier (control carrier) of the PPN in all
systems, except for the UN330B which is found only in high and critical reliability
systems. In high and critical reliability systems, the PPN B carrier duplicates
exactly the configuration of the A carrier, making two identical SPE complexes.
This duplication allows the system to recover from many faults, and enables
troubleshooting and repairing of SPE components without interrupting service.
The Tone-Clock circuit pack also resides on the control carrier, and is also
duplicated. However, it is not considered a part of the SPE. Although the
SPE-Select switches control Tone-Clock selection, its duplication strategy differs
from that of the SPE. See the ‘‘TDM-CLK (TDM Bus Clock)’’
and ‘‘TONE-BD
(Tone-Clock Circuit Pack)’’ sections in Chapter 9, ‘‘Maintenance Object Repair
Procedures’’ for details.
Duplicated SPEs employ an active/standby strategy. At any one time, one SPE, A
or B, is designated active and controls the switch services network. The other
SPE, designated standby, is not required for switch service but remains ready to
become active and resume control of service should a service-affecting failure
occur in the active SPE. This action is termed an SPE interchange. It is important
that the standby SPE be kept as available as possible to allow for a rapid
interchange.
Table 1-4. SPE Circuit Packs and Maintenance Objects
Apparatus
Code Circuit Pack Name
Associated
Maintenance Objects
TN1648 System Access and
Maintenance
SYSAM
UN330B Duplication Interface DUPINT,
DUP-CHL
UN331B Processor PROCR
TN1650B Memory MEM-BD
TN1655 Packet PKT-INT
UN332 Mass Storage System/
Network Control (MSSNET)
H-ADAPTR,
SW-CTL
TN1657 Disk Drive DISK
TN1656 Tape Drive TAPE
STBY-SPE
STO-DATA
