DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Architecture
1-21SPE Duplication
1
SPE software. SMM also ensures that when handshake communication has been
down for an extended p eriod, the standby SPE will transition into the SPE-down
state.
Handshake Communication
Every 30 seconds, the active SPE sends a handshake requ est message to SMM
and waits for SMM to respond with a hand shake response message. This
message transmission occu rs across the Duplication Interfac e circuit packs and
their interconnecting c able. As long as SMM responds to t hese regular
handshake request messages , handshake communication i s considered

up

as
reported on the status spe sc reen.
The physical path of handsha ke communication is illustrated below. Hardware
problems at any point in this route c ould interfere with handshake
communication. If the stand by SPE fails to respond to four successive
handshake requests, hand shake communication is consi dered down. A major
alarm is logged ag ainst STBY-SPE with error type 1 logged . The status spe
screen will indicate that hand shake is down. It is then no longer p ossible to
communicate with the stand by SPE. Maintenance testing of the standby b y the
acti ve SPE (or by c ommand ) is d isc ontin ued, and th e erro r and alarm logs
become outdated for standby comp onents.
Handshake communication fa ilure is a severe and rare condition. It is d ue to
either a failure of Duplication Interfac e hardware or a catastrophic failure of the
standby SPE. As long as the active SPE is not locked b y the switches, software
attempts every 30 second s, to re-establish handshake communi cation.
When the SPEs are locked with the switches, handshake communic ation is
physically impossib le, but no alarm is raised. When the stand by is busied out,
handshake communication s hould remain up, but in any c ase, only the busyout
WARNING alarm will be raised.
Whenev er the activ e SPE has u nder gone a rest art (l evels 1 -5), h ands hake i s
technically consid ered down during and just after the restart. After a level 1 (hot)
restart, if there are no standby SPE problems, handshake c ommunication should
be restored within 30 second s. After active-SPE restarts of levels 2 and up,
handshake should be restored within 3 minutes of G3-MT re-enabling.
The ac tive SPE k eeps hardw are c onfig urat ion an d vin tage d ata a bout the
comp onen ts of t he stan dby SPE. This d ata c an b e acc essed with list
configuration control. Whenever handshake is down, this data may b e out of
date. Whenever handshake has been d own and is restored, the active SPE
requ ests st andb y SPE sof tware to tra nsmit the c urrent versi on of t his d ata. Th e
data is the n store d in a ctiv e SPE memo ry.
Failure to use the lock-and-power- d own method for standby c ircuit pack
replacement can lead to incorrect standby component hardware config uration
and vintage data.