Switchback to Call Agent (CUCM): H.323 and MGCP Approach

One topic is ‘HOT’ on the discussion forums now a days and that is how MGCP and H.323 gateway switchback to backup CUCM when primary is down or switchback to primary CUCM when it’s up again. I have tested some scenarios on my lab and the following procedures can be followed for such requirements:

For H323 GW

The command ‘h225 timeout tcp establish x’ plays the roll here within dial-peers. If any call agent goes down while in a call, after configurable number of seconds if searches other dial-peers with the same destination-pattern configured and switchback to that dial-peer.
!
voice class h323 1
h225 timeout tcp establish 3
!
dial-peer voice 1 voip
destination-pattern 3…
voice-class h323 1
session target ipv4:SUB
no vad
!
!
dial-peer voice 2 voip
destination-pattern 3…
voice-class h323 1
session target ipv4:PUB
no vad
preference 1
!

For MGCP GW

Either manually configure this on gateway (if we don’t download the configuration with the command ccm-manager config):
!
ccm-manager switchback immediate
!

Or configuring it on the MGCP GW page at CUCM (must need the command ccm-manager config):

“Switchback Timing* = Immediate”,  It’s ‘Graceful’ by default.

This is just to mention that: you can switchover to backup Call Agent manually with the command ‘ccm-manager switchover-to-backup’ if the command ‘ccm-manager switchover immediate/graceful/scheduled’ is already not configured.

happy labbing! 🙂

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If you want to know what MTP (Media Termination Point) does: I loved this discussion!

I was surfing the CSC (Cisco Support Community) discussions and stopped while this discussion took my attention.

https://supportforums.cisco.com/thread/2028260

You can also kill some of your time if you still have confusion on what Media Termination Point (MTP) does both in CUCM or IOS.

Frustrating!

Tell me why i won’t be frustrated when Indian embassy rejected my visa application, now applied for UAE and now i have to wait for long 4/5 days more to get confirmation on that! The weird situation is, if they also reject my application i won’t be able to sit for lab within 2 months. 😦