[Serusers] Who is violating SIP protocol here, SER or voice-ISP?

[Robert C. Auch]

Jeremy,
I don't know if you got this answered already or not - I'm not seeing
the subject popping back up...

My PBX Gateway was doing the same kind of thing: calls were timing out
after about 1 minute (45 seconds once, and 60 seconds another time).  It
turns out that the loose-route processing wasn't working right.  If I
put the:
if (loose_route()) {
 	if (!t_relay()) {
		sl_reply_error();
	};
	break;
};

Line after the registration and "if (uri==myself){stuff}; blocks, then
I'd time out.  If the Loose_route() processing was up earlier, near the
top of the ser.cfg (like in the demo), then my PBX Gateway wouldn't time
the calls out.

Rob

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> -----Original Message-----
> From: serusers-bounces at lists.iptel.org 
> [mailto:serusers-bounces at lists.iptel.org] On Behalf Of Jeremy M. Dolan
> Sent: Thursday, October 07, 2004 11:54 AM
> To: serusers at lists.iptel.org
> Subject: [Serusers] Who is violating SIP protocol here, SER 
> or voice-ISP?
> 
> I will attach a full SIP conversation to this e-mail, but 
> here is the summary of what seems to be happening.
> 
> I place a call from my phone here, behind NAT. This contacts 
> a SER server with nathelper/rtpproxy out on the 'net, which 
> then forwards the requests to Masergy (www.masergy.com), who 
> provide us with LD VoIP service. Everything proceeds fine 
> until the "OK" reply from Masergy signalling the call has 
> been answered. Here's the transaction there:
> 
>    Masergy port 29436 -> SER port 5060 "OK"
>    SER port 5060 -> My Phone port 5060 "OK"
>    My Phone port 5060 -> SER port 5060 "ACK"
>    SER port 5060 -> Masergy port 29436 "ACK"
> 
> Masergy never receives that last packet.
> 
> However, my phone receives all of the information it needs to 
> establish the RTP connection. It does so, and the call 
> appears to be working fine.
> Meanwhile, Masergy's SIP server continues to resend "SIP/2.0 200 OK"
> messages (still from port 29436) every few seconds, waiting 
> for a reply.
> After ~35 seconds of not hearing back, it assumes the worst 
> and sends a "BYE", tearing down a call that was going swell, 
> as far as the two humans involved were concerned.
> 
> I've spoken with the relevant tech at Masergy, and their 
> determination is that our SIP proxy should be sending all SIP 
> traffic to port 5060, regardless of what they may be 
> transmitting from.
> 
> I just built the very latest CVS version of SER 
> (0.8.99-dev8), and am seeing the same behavior. Is this a 
> protocol violation on either side?
> (Transmitting to a non-5060 port, or not listening for a 
> reply on a port that was just transmitted from). Is there a 
> way to force SER to always use 5060? (Which itself probably 
> breaks protocol for some cases, which we aren't currently 
> dealing with).
> 
> Thank you for any info.
> 
> Jeremy
> 
> --
> Jeremy M. Dolan <mailto:jmd at pobox.com> <http://jmd.us/>
> PGP: 1024D/3C68A1BA 9470 210C A476 FFBB 6D11  0223 0D1C ABFC 3C68 A1BA
> 
>