Hello,
It's been a little while since I last posted, but this will look familiar to those who remember:
The scenario is this:
Phone sends openser an invite, which tries to set things up with the PSTN gateway, which is unresponsive(*), and so it sends back to the Phone:
SIP/2.0 503 Service not available
and the Phone sends back an ACK.
What should I do with that ACK?
One possibility is to do nothing, another possibility is to t_relay() it.
What suprised me was that when I do nothing then another "SIP/2.0 503 Service not available" message is automagically sent to the Phone. So, that can't be the right thing to do.
Meanwhile, when I t_relay() it then things usually work. But this doesn't seem like the right thing to do, since the ACK is meant for the very box on which I'm doing the t_relay().
So, what's the story?
Thanks, -mark
(*)don't worry about why the PSTN gateway is unresponsive.