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 Swit ch Pro cess ing Ele ment ( SPE) con sists of the follo wing circ uit p acks .
These circuit packs resid e on the A carrier (control carrier) of the PPN in all
systems, except for the UN330B whic h is found only in high and c ritical reliability
systems. In high and cr itical reliability systems, the PPN B carrier d uplicates
exac tly th e con figur ation of the A car rier, m aking two i dent ical SPE comp lexes .
This duplication allows the system to rec over from many faults, and enables
troub lesho oting and repai ring of SPE co mpon ents w ithout inter rupt ing s ervic e.
The Tone-Clock circuit pack also resides on the control carrier, and is also
duplicated . However, it is not considered a p art of the SPE. Although the
SPE-Select switches control Tone-Clock selection, its duplic ation 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, ‘��Maintenan ce Object Repair
Procedures’’ for details.
Dupl icat ed SPEs e mploy an ac tive/ stand by s trate gy. At a ny one time, one SPE, A
or B, is designated ac tive 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 s ervice-affecting failure
occ ur in t he ac tive SPE. This ac tion i s ter med a n SPE inte rchan ge. I t is im port ant
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 Pa cket PKT-INT
UN332 Mass Storage System/
Network Control (MSSNET) H-ADAPTR,
SW-CTL
TN1657 Disk Drive DISK
TN1656 Tap e Dri ve TAPE
STBY-SPE
STO-DATA