Ringback tone issue with call transferred through Unity Connection.

[Remon Adel]

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 .

Our action
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 

Result :
Same issue 

Kindly check SIP VGW logs below  debugs
debug voip ccapi inout
debug ccsip message

[R0g22]

Working asa designed. Once the call has been answered by the CUC call handler, a "200 OK" marks the dialog establishment. With SIP, none of the devices will send a '"180" or "183" in-dialog.
A couple of workarounds -

1. Invoke Annunciator on CUCM for proxy ring back.
2. Use H.323.

[Remon Adel]

Hello Nipun
Thanks for your support.
I already configured Sip trunk with media resources contain Annunciator .

[Ayodeji Okanlawon]

Nipun,

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?