DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Object Repair Procedures
9-841EXP-PN (Expansion Port Network)
9
syste m, a Pac ket I nterf ace c irc uit p ack f ailur e cau ses an SPE interc han ge, w hich
allows the link to be recovered q uickly over the newly active Packet Inter face. Or
on a Center Stage Switch, a link carried on one of the multiple fibers
interconnecting the switc h nodes may be rerouted over an alternate fiber.
If the EAL is recovered quickly, the EPN Warm Restart returns the EPN to service
with minimal effects on user service. If the EAL can not be recovered quic kly, the
EPN is taken out-of-service and an EPN Reset Level 2 (EPN Cold Restart) is
required to return it to service.
EPN Cold Restarts
If the PPN to EPN link has failed and has not been recovered within 30 se conds,
the EPN is taken out of service and can be b rought back into servic e only with an
EPN Reset Level 2 (EPN Cold Restart). Effects of an EPN Cold Restart include a
reset of all circuit pac ks in the EPN, and the disconnection of all c alls to or from
the EPN. Calls with both endpoints within the EPN are dropped upon recovery.
EPN Restart Escalation
EPN restarts follow an escalation strategy controlled by maintenance software.
Whenever a request for an EPN Reset Level 1 (EPN Warm Restart) is made,
software checks to see if the restart should be escalated to an EPN Reset Level 2
(EPN Cold Restart). If any of the following are true, the restart is escalated:
■At least two level 1 restarts have occurred and less than two hours has
elapsed since the last occurrence.
■Current EPN conditions do not allow a level 1 restart, suc h as when the
EPN is out-of-service.
■Less than 3 minutes has elapsed sinc e the last EPN Cold Restart,
indicating that the EPN is unstable.
If two EPN Cold Restarts have been executed i n less than an hour and the link is
functional, but the EPN has not recovered to an in-servic e state, a MAJOR alarm
is raised against EXP-PN, and the EPN is put into Emergency Transfer by system
software. (Software can invoke EPN Emergency Transfer only when the link to the
EPN is up. If the link is down, the hardware automatically i nvokes Emergency
Transfer 1 minute after it detects a link failure).
Connectivity Alarming
When an EPN is ou t of se rvic e, a MA JOR EXP-PN a larm is rai sed a gain st tha t
EPN. An EPN can only be alarmed if it is out of service
and
the fiber between the
PPN and EPN is up. If the fiber from the PPN to the Center Stage Switch is down
(by removing it from administration, fo r example), all EPNs are lost but not
alarmed, since they are not the c ause of the problem. If, however, connec tivity is
restored and the EPN fails to recover, the EPN is alarmed.