VG450 MGCP fallback

[Paul Austin]

Hi Folks, Can I use a VG450 in MGCP fallback mode to register to an ISR 4XXX CUBE in SRST mode? I am sure i have it all configured and when I isolate the VG450, I can see the MGCP try the CUCM's but it never tries the ISR. Yes I have created a SRST reference of the ISR, created a new DP with that SRST reference and applied to the analogue phones.

If possible can you supply a sample config for both so I can cross-check?

Best Regards

Paul

[Jonathan Schulenberg]

That's not quite how it works. MGCP fallback drops the gateway into the local call application (i.e. dial-peers). You would need to build a SIP or H.323 dial-peer toward the gateway where SRST and PSTN access exist.

If your next question is how incoming calls should be routed to the VG during fallback, this is entirely up to the dial-peer configuration on your PSTN gateway. The way I go about this is using SIP Options Keepalive on the VoIP dial-peers toward CUCM and the VG, dial-peer hunt 2, and applying preferences on the dial-peers so that CUCM is better/lower preference than the VG. That way if CUCM goes down the dial-peer for it will busyout and the PSTN gateway will offer the call to the VG instead.

[Paul Austin]

Thanks for that. Sorry since I my OP, I have already configured it so the analogue ports fallback to the Vg450 then us a dial-peer to forward calls to the ISR.

So, does it work? The design guide and release notes say yes. Do you have a working config I can compare?

Thanks