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Community Member

PRI redundancy issue with MGCP

CCM3.3(3) with 2* MGCP Gateways integrated with a PBX via 4 *PRI T1.

The MGCP GW1 has PRI1 and PRI3 to the PBX, and the MGCP GW2 has PRI2 and PRI4 to the PBX. Based on the route plan on the PBX, the PBX will always try to route incoming calls to the highest priority T1:PRI4 first, then PRI3, PRI2 and PRI1.

If the MGCP GW2 lost connection to the CallManager, dose the MGCP GW2 automatically set the PRI D-channel down to prevent the PBX from routing incoming calls to PRI 4/ PRI 2, and PBX will route incoming calls to other active T1:PRI1 /PRI3?

If not, all incoming calls will be lost as the PBX routes all calls to PRI 4 first.

Does Cisco MGCP Gateway support the features? And How to handle this situation.

Any comments are very appreciated.

Community Member

Re: PRI redundancy issue with MGCP

If the gateway is not able to register with the Call Manager it will not 'shut down' the D-channel. The MGCP IOS gateway handles up to Layer 2 signaling on it own. What will happen is that no call setup will happen since the Q.931 messages are backhauled to the CCM. Since those messges will not be answered, call setup will not happen on the gateway.

Now your PBX should handle this and move on to the next PRI in the trunk group (since there was no call setup).

Community Member

Re: PRI redundancy issue with MGCP


But this is a very important feature to support inbound calls redundancy for multiple Gateway deployment.

How Cisco handle this situation automatically or supposed to support in future release?

Community Member

Re: PRI redundancy issue with MGCP

Call Manager has very little to do with how inbound calls are sent to the gateways. That is more of a PSTN/PBX issue.

With the PSTN/PBX you can just set all of your circuits in one trunk group that the PSTN/PBX will route calls to. That will give you the ability to use the first available trunk.

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