CCM voice gw H.323 failover issue

[srikrishnan.b]

Hi!

We have a Cisco CallManager cluster with redundant H.323 Voice gateways for

PSTN connectivity. The CCM version is 4.1(2) and the VG's are Cisco 3745

routers running 12.3 mainline IP VOICE image. When the PRI links on the

first VG goes down, the CCM does not forward the calls to the redundant VG.

The route groups, lists and patterns are configured properly on the CCM.

Also the dial-peer and POTS config are proper on both the VG's. The problem

is only with outbound calls. We tried upgrading the IOS on the VG, still no

luck.

Is this problem related with the IOS feature set, like the IP Plus? Pls

suggest...

Rgds.

Sri,

[megaco123]

Are you running any Gatekeepers on the network or is this just H323 to PSTN gateways?

Have you tried debuging the H225/Q931 messages?

If you force the second gateway to take calls (i.e. promoting it to become a primary link) do you still have the problem? Also do you see H225 events on the primary server.

When the primary link goes down you should not be getting a H225 setup ack back from the Primary gateway so its something to look at. Log on and see if CM is talking to it.

Hope this helps?

[srikrishnan.b]

Hi!

Thanks for the suggestion.

Here goes:

Have you tried debuging the H225/Q931 messages?

Yes.

Tried h225/q931.

Not getting q931 response when primary VG links go down, but getting h225 response on the primary VG...

Same issue persists when the secondary gateway is made active.

We observe h225 messages between the CM and primary VG, when the primary VG links go down.

So, is this an issue related to the CCM or VG ?

Pls suggest.

Also, we need to try out the service parameter option "stop routing on user busy" flag set to false...

Rgds,

Sri,

[srikrishnan.b]

Hi!

We r not running any Gatekeepers on the network. It is just H323 to PSTN gateways...

Rgds,

Sri,

[dr3297]

Try setting the "stop routing on user busy flag" to false.

This is supposed to only be for intercluster trunks. but i have see it effect other h323 and h225 interactions with callmanger.

Changing this also resolved a simular issues I had with callmanger 3.3.3 a few years ago.

[sdmello]

go to CCM Admin page > Service > Service Parameters > choose CallManager Service

> look for Clusterwide Parameters (Route Plan) > Stop Routing On User Busy

Flag* > Set it to FALSE > at the same place : Stop Routing on Unallocated Number

Flag* > set it to FALSE > update >