ICM Managed Transfers using CVP thru gateway disconnect after 10 seconds

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We had two customers now that had this issue.  Basic ICM script with CVP where calls are presented a simple auto attendant menu.  When calls are transferred outside of the CUCM to a TDM device it would disconnect after two rings (10 seconds).  If the device answered before that time, no problems.  Adding "Requery" to the route made no difference.

Everything worked fine when the system was turned up.  Became intermittent, then eventually happened to every call.  Two completely different customers with the same issue and deterioration.

Review of log data pointed to CCM sending release after 10 seconds of setup sent out to the TDM device due to media exchange timer expiration.

During early media scenario, the H245 address will be sent in Call Proceeding or Alerting message to CVP. If CVP doesn't establish the H245 connection within 12 seconds, the call will get disconnected by CCM. In slow start cases, the CVP is expecting the H245 address in Connect and therefore, it doesn't establish the H245 connection until after the call is picked up.

The fix was:

1. In VBadmin, set MediaWaitForConnect on and test it.

2. Send call to a GW instead of CCM for that extension/Label and then let it route to TDM number.

The mediaWaitForConnect = true flag in the outgoing Setup message from CVP forces the CCM to send the H245 address in Connect only and therefore avoid this situation and disconnect in the Call-Forward case. 

Bottom line it helps when not getting proper alerting and why it worked sometimes, but not always.

Reference Defect: CSCsi70794 which was supposed to have been fixed in our version of 7.0(1)  Must now be a feature

I have this problem too.
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jpsweeney77 Thu, 01/28/2010 - 08:17

Thanks for posting this info to the forum! Not to hijack this post but we had a similar situation when upgrading a customer to 7.0 a couple of years back. Turns out our issue was related to the Voice Class Codec commands on the gw's. If I recall though, our disconnect was occuring after about 12 seconds.

Voice Codec class configuration should be symmetrical on the Ingress gateway and the Egress gateway. Use the voice class codec command to define the list of codecs available and the order in which they should be tried.

For example, if G.729 is the preferred codec, the codec class should be configured to preferG.729 and then G.711 on both gateways as shown in the example below. Codec class 2 is usedfor Codec negotiation.

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