I have a UCM version 8.02 utilizing an internal SIP Trunk to an IVR (server). The SIP Trunk functionality works well to the IVR, but if I initiate a transfer from the IVR to an outside number the call fails. The call from the IVR utilizing a SIP trunk attempts to transfer to my 2811 voice gateway configured as MGCP. The 2811 has 2 PRI trunks connected to a CO simulator (Hammer), which through scripting will answer the calls. I can make an outbound call through the PRI Trunk group from the IVR, IP phone or SIP phone connected to the UCM but if I try to initiate a call transfer from the IVR using the SIP trunk, the call fails.
Here is the strange part, if I connect the UCM and IVR to an H.323 gateway instead of the MGCP gateway the call transfer works like a champ.
This is a Lab environment so there is no Calling Search Space setup.
I'm guessing there is a config issue with the 2811? But not sure on that.
Any help would be greatly appreciated.