I setup a obihai 200 back in November. It's been working great until 3 days ago.
No changes have been made to the config (it's at my parents place), so I get a (cell) call from them saying they can't make any calls.
I have 2 service providers configured, 1. incoming and local calls 2. outgoing, everywhere else.
I logged in and I see SP1 is fine, however SP2 says:
Register Failed: No Response From Server
So I went over, connected to their network, and configured sip on my phone. I was able to make calls, so the service provider is reachable and working from the network.
Is there any reason why obihai device would say no response when it is reachable from other devices on the network?
Next time, try to change the X_UserAgentPort for the offending SP, while the problem is happening. If that solves the problem, it was caused by corrupted NAT tables in your router.