Call Mgr Fall Back - delay on phone returning

[Yort Mantup]

I have a site configured with H323.   They have a 2801 router running 8 phones and using a couple of POTS lines.  They recently lost power and when the power was restored the network came up but it took 20 minutes for the phone to switch back from fall-back mode.  We are on CM 8.5.  Is there anything in the config itself or in call manager that would cause this long of a delay?

[George Thomas]

I would check the Connection Monitor duration to see if that was changed to cause this behavior. Its under the Device pool settings.

[Francisco Granados]

Indeed, that's a good place to start. 

Where you able to log into the router/switch? I had an issue once where after a power outage our MPLS/EIGRP would take about 20 minutes to reestablish relationship so everything stayed down for longer than expected.

[Yort Mantup]

I did not have a chance to try and login to the router after connection was re-established so I cannot answer that.  The Connection Monitor Duration is blank.

[Francisco Granados]

Before diving into Call manager/IP telephony too much, I would make sure the layer 3 connectivity between your IP phones and HQ site was up. I understand this is almost impossible to do after the fact, perhaps it will be best to schedule a planned fail over to test. It is very likely that the keep alives were not reaching CUCM due to an underlying issue with your network, and not the configuration itself.

Thanks,

Frank

[Yort Mantup]

I would agree and will put it on the todo list.  I did not realize that setting existed in CM so thanks for that also.