DEFINITY ECS Release 8.2 Maintenance for R8.2csi
555-233-119 Issue 1
April 2000
Maintenance for csi systems
1-138Troubleshooting Multimedia Call Handling (MMCH)
1
Specifically, PictureTel System 4000 endpoints seem to be the most sensitive to
instability. The Lucent Technologies Vistium also disconnects fa irly infrequently.
Last, the CLI Rembrandt II VP freezes video and waits for framing to be
recovered .
Network Configuration Concerns with
Synchronization
When auditing a network for synchronization, avoid unnecessary hops. Thus, a
switch providing star-configuration sync hronization is preferred over a
daisy-chain config uration. Additionally, if there are DEFINITY PBXs that have
EPNs, synchronization should be provid ed to sub nodes from t he same port
network through which the PBX receives its synchronizatio n. Passing
synchronization through the PBX Expansion Interface ad ds an unnecessary hop
to the path and creates another potential point of failure.
Expansion Interface Duplication
If a customer’s network uses PBX EPNs with duplicated Expansi on Interfaces,
scheduled switc hing of the Expansion Interfac e links should be disa bled on the
PBX via change system-parameters maintenance. When scheduled
maintenance runs and switche s the links, there is a brief corrup tion of the data
path. If endpoints have active calls when the switc h occurs, this corrup tion of the
data path causes Px64 handshake p roblems, which lead to th e endpoints losing
video source status, and s ometimes disconnectin g as describ ed above.
Disabling the EI switching is in the customer’s best interest to p revent the
disruption of the Px64 data stream. The customer will g et the same level of alarm
indications and main tenance on the EI links, regardless of the stat us of
scheduled switc hing.
PRI D-Channel Backup
A somewhat unlikely source of call stab ility problems oc cur where the
translations for PRI D-channel Backup betwee n two non-MCU switches were
incorrect. As an example, on switc h A, DS1 1A10 was designated as the p rimary
source, and on switch B, the corresponding DS1 was designated as the
secondary source. When sched uled maintenance was run on the switc h that had
an active standby D-c hannel, an audit disc onnected some calls using the link.
The problem was corrected when the D-channel primary/ secondary assig nments
matched.
Processor Duplication on the PBX
Do not enable the PI link switch on sched uled maintenance. This can c ause link
stability problems on the A ccunet Bandwid th Controller (ABC).