[Asterisk-Users] SIP phone stops ringing

[Tim A Hall-Woodcock]

I have a working Asterix system in a very simple configuration, just 
using a VOIPTalk account to make and receive calls with two extensions. 
Everything works OK but....

I have got a strange problem when making a call to a PSTN number form 
Asterisk. When I dial out from a SIP phone it rings no problem, as soon 
as the other end is connected i.e. my mobile rings, the ringing sound 
on the SIP phone stops. I can answer the call at any point and it all 
works fine. Why does the SIP phone stop ringing, I have tried different 
SIP phones with exactly the same result. It happens when Asterisk 
reports:

-- SIP/voiptalk-out-7505 is making progress passing it to SIP/2202-a5db

I use:

exten => _08.,1,Dial(SIP/${EXTEN:2}@voiptalk-out,60,tTr)

Removing the 'r' stops it ringing completely. Adding 'm' makes MOH kick 
in and this never stops, only when the call is answered.

Strange thing is it was fine yesterday. Incoming calls ring fine and 
calls between extensions ring fine.

What could be going wrong?

Tim.