[asterisk-users] Maximum retries exceeded on transmission

[Olle E Johansson]

13 apr 2007 kl. 16.45 skrev Brian Jones:

> I've encountered a similar problem with Cisco equipment.  The Cisco  
> proxy was not replying to Asterisk with an ACK after * sent an OK.
>
> Since version 1.2.14, * was changed so that not receiving an ACK to  
> an OK is considered a FATAL error.
>
> The specific change that causes this problem is in sip_answer() in  
> chan_sip.c:
>
> res = transmit_response_with_sdp(p, "200 OK", &p->initreq, 2);
>
> Changing the 2 to a 1 will probably fix it.  Note that this is NOT  
> a bug in * but improper implementations--either caused by latency,  
> or a software bug (not sending an ACK).  Perhaps it might be  
> beneficial to have an option in sip.conf to change how * handles  
> not receiving an ACK?  I know... it's someone else's problem, but  
> might help those of us stuck with buggy implementations in  
> production environments. :)
>
Answering late, but still answering to this mail from april that was  
highlighted to me by an Asterisk user.
This change is *not recommended* and will in worst case cause  
Asterisk to have channels hanging with open UDP ports
and eventually break your system.

Not sending an ACK on an INVITE-200 OK- ACK transaction is and should  
be a fatal error. If you change this, you really
need to know what you're up to. (And don't request help on the bug  
tracker :-) )

/Olle