CUCM - connectivity issues with VGW after LAN outage.

[Magnus Holsting]

Hello.

I have an error ticket from a customer who claims, that after every LAN outage, Cisco Unified Communication Manager can't communicate with VGW's (They lose the ability to call outside).

They resolve the issue by restarting the CUCM. Untill the restart, they have a critical hotline number, which doesn't work (a DN forwarded to a mobile phone).

Does anyone have any experience with this type of issue - or can think of what the root cause is?

Thank you very much.

/Magnus

[Manish Gogna]

Hi Magnus,

It could be an issue with the gateway endpoints losing registration with cucm ( in case on SCCP / MGCP ). Did you check the status of endpoints on CUCM gateway page after the outage?

For h323 or SIP, a trace or debug for a failed call and basic connectivity tests would have been helpful.

HTH

Manish

[Magnus Holsting]

Hi Manish.

Thank you very much for the reply.

My thoughts have been on the Gateway endpoints aswell (MGCP), but I have a little trouble figuring out how they can fail to registrer and how a restart of the cucm could help them registrer.

- All phones and all internal call features and calls works after outage.

I have yet to se the issue live, since it's a large environment with no room for outage, but it might help to debug on the endpoint registration process - at least to get further by eleminating an error source.

/Magnus

[Brian Meade]

I would set up "debug mgcp packet" on the gateway and set it up to send it all to a syslog server.  I would then pull those logs and CallManager traces from the next outage.  Make sure the trace level is set to Detailed.