More MoH talk with ITSP and CUBE’s. I mentioned in earlier posts that playing MoH without an MTP can be achieved by creating sip-profiles to manipulate some of the SDP attributes. I recently have another MoH issues where the MoH stream was simply dead air or silent. Of course enabling the MTP on the SIP Trunk in CUCM resolved the issue.. however we want to avoid forcing an MTP for all calls.

I resolved this by removing the cmd “pass-thru content sdp” under the Voice Service Voip -> SIP config menu. In this case the sip-profile route was not working for me.. The above cmd negates the Gateway in the negotiation process, hence passing through codec and mtp negotiations. The potential problem here is the mismatch between CUCM and ITSP, we want the gateway to participate and effectively inter-work between CUCM and the ITSP.

If you have other options or methods that work to combat silence in MoH using an ITSP, please post.