Hello all,

My customer has a CVP solution using SIP with CUP and Unified CM 6. They also have a separate Unified CM cluster for IPT users. So far so good.

They now have a requirement to have incoming contact centre calls routed via the IPT cluster. I.e.

TDM PBX- pri – mgcp (QSig) – IPT CUCM Cluster
-----
TRUNK
-----
UCCE CUCM Cluster ----CUP --- ICM / CVP

Questions are:

Q1) Is this a supported protocol flow for incoming calls to CVP>UCCE? I understand that it is supported for calls to arrive at CVP from Unified CM via an MGCP controlled GW (with caveats) but what if these calls come via a different cluster with a trunk between them.

Q2) If it is supported, are the recommendations for the trunk configuration. Direct H323, direct SIP or GK controlled H323?

Q3) Are there any specific caveats of this approach? e.g.

• Would we need MTP if SIP trunk?
• What about DTMF?

It is LAN all the way between the ingress GW, 2 clusters, CUP servers, CVP servers and VXML GWs...

Thanks Paul - much appreciated. I have a couple of follow on questions here.

1) Is there any recommendation from a CCBU perspective on what protocol the trunk should be between the two Unified CM clusters? I.e. SIP/H323/GK controlled. Does it matter, even taking into account DTMF? I'd imagine a SIP trunk would be sensible as we have a SIP trunk to the CUP server being used directly afterwards by the contact centre cluster...?

Note that it is possible that SCCP IP phones in the IPT cluster will want to call into the contact centre too over the trunk link between the two clusters.

2) You mention that endpoints should be SIP. However in this case the ingress GW will be MGCP controlled and there is a possibility (as mentioned above) that callers could be SCCP phones on the other side of an intercluster trunk link...will this cause any issues for DTMF?

Thanks again,
Andrew