[OpenSIPS-Users] Why the best response is 408 instead of 486 when parallel forking?

[Iñaki Baz Castillo]

Hi, I've a UA1 that is registered in two locations, UA1-a and UA1-b.
UA1-b is crashed and doesn't listen to SIP anymore.

Other UA calls UA1 and OpenSIPS does parallel forking, so it gets 180 from 
UA1-a.

UA1-a replies 486, but OpenSIPS decides to reply "408 Timeout" to the caller.

Why is 408 chosen over 486? IMHO it doesn't make sense since this 408 is 
created by OpenSIPS itself, it's not a reply from downstream and basically 
means "error contacting a branch".
Since there is an *alive* branch (UA1-a), why inform the caller about an error 
instead of replying the 486 choosen by UA1-a?

This issue is common in some cases when registering behind NAT in routers that 
assign a different mapped port each time the phone switches on (so the 
location table has many contacts for that AoR, but most of them are dead if 
the phone didn't de-register them when switching off).

-- 
Iñaki Baz Castillo