Call dropped when party answers

[Hortoristic]

I have a 202, and my GV is who people call and it forwards to Callcentric when then is forwarded as DID and rings SP2 on my OBI.

Lately; 40% of the time as we answer the call; it hangs up - the party calls right back and usually when its answered, it works ok.

Not sure what to try.  I also am using OBILINE to connect Comcast box for outgoing calls (got free Comcast so all outgoing with them) - but that shouldn't mess with incoming.

Any ideas?

[Mango]

Some possibilities I can think of that could cause this:

1) RTP fails to be established, and so the call drops.
2) Malfunctioning SIP ALG.
3) Electrical problem with your phone.

Let's start with 1).  Navigate to Service Providers >> ITSP Profile X >> RTP.  Make a note of LocalPortMin and LocalPortMax.

Using your router, forward the UDP port range LocalPortMin-LocalPortMax to your OBi.  If your OBi does not have a static IP, you will need to assign one to it.

Let me know if that works, or not.