we have ring back tone issue with below scenario
PSTN -----PRI (E1)----SIP VGW--- SIP trunk-----CUCM----SIP TRUNK-----CUC(AA)---Transferred Calls to Internal IP Phone.
When incoming call trough above scenario and Transferred by Unity AA to internal extension , Caller not get ring back tone .
1-Enable PRACK on SIP trunk between GW and CUCM also on SIP TRUNK between CUCM and CUC
2-Enable PRACK on Voice Gateway which enabled by default
Kindly check SIP VGW logs below debugs
debug voip ccapi inout
debug ccsip message
I dont think this ia working as designed. Normally the first leg of the call ie call to AA will not get a ring back but the transfer to the phone should generate ring back to the caller.
My first question is does ring back work on normal calls from the PSTN?