No Ringback on SIP Trunks

[sanmar]

I recently switched over to SIP trunks from PRI, after a couple of hiccups the only issue left is that we don't always get a ringback when we dial out. Sometimes it works and sometimes it doesn't. I am using an MBG and did some trace routes to send to SIP provider and they are telling me they are sending the SIP 180ringing back to the MBG. Any help will be appreciated. Thanks

[mhumphries]

i have a similar issue.  we still have out PRIs however we have added SIP trunks to the mix.  i can make a call and it completes as expected. however there is no ring back.  did you ever get to the bottom of your issue?  we are not using a border gateway. i have the SIP trunks coming through the firewall with 1-to-1 NAT.  ports 5060-5061 are open to the VMCD, as well as the RTP ports.

[x-man]

What RTP ports are you using and do they match what the provider specifies?

[mhumphries]

does the ringing come through the SIP Trunk as RTP?  when i spoke to the provider they did not believe that it did.  that the 180 ringing should trigger the Mitel to provide the ringing???

[x-man]

Hmmm, I was under the construct that the 180 ringback was sent as RTP from the far end subscriber....probably wrong though.