Hello,
I have these IPPhone models: 7821, 8841, 8851. I make Calls with this logic:
SIP IP phone ---- one route pattern exact match ---- SIP Trunk --- SIP Gateway --- one dial-peer exact match --- E1 (PSTN).
When I make calls I observe that it takes too long to send the call to the gateway. The route pattern match correctly, I write the FAC and after that it takes aproximately 7 seconds to give me the calling sound. With 7821 IPPhone in these 7 seconds I see the behavior on the attached photo.
Also, I have another gateway (as H323 in CUCM) and this doesn't show this issue. Actually, It routes the call pretty fast.
Attached are my gateway config and my SIP Trunk config.