SIP Trunk TCP/UDP

[GOBrien-IWS]

All of the sudden we weren't able to make or receive calls on one of our SIP trunks. Just got off with the provider and what we found was when the invite came via TCP it got no answer, but when he forced UDP, it came through fine. Checking my V11 config shows TCP and UPD enable for port 5060, but in System status, it shows the layer 4 protocol as UDP only. Has anyone seen this?

 

[derfloh]

It’s configured in your trunk.

If you use TCP for Trunk and Clients it can happen that IPO sees an Invite from a trunk as invite from a client and drops it

IP Office remote service
IP Office certificate check
CLI based call blocking
SCN fallback over PSTN