[OpenSIPS-Users] Asterisk reinvite confuses Mediaproxy

[Jeff Pyle]

Hi Ruud,

On 7/20/09 6:29 AM, "Ruud Klaver" <ruud at ag-projects.com> wrote:

> What I said is still valid, both endpoints SHOULD start sending to the
> new ip/port destination after the re-INVITE transaction has finished.
> Looking at the mediaproxy logs you sent, all is fine up to the point
> where the caller is about to receive the 200 OK for the re-INVITE.
> After it did receive it, mediaproxy-relay display the following line:
> 
> debug: Got traffic information for stream: (audio) 44.55.66.30:13504
> (RTP: 22.33.44.82:28140, RTCP: Unknown) <-> 22.33.44.89:16392 <->
> 22.33.44.89:16394 <-> 33.44.55.122:17328 (RTP: 33.44.55.122:17328,
> RTCP: Unknown)
> 
> You can see that the relay got RTP from the caller side from the old
> ip/port, that is the asterisk box, while in the re-INVITE it proposed
> to change this to 44.55.66.30:13504. This must mean that asterisk
> takes the ip/port from the 200 OK, which is newly allocated on the
> relay, and starts sending to this directly. What should have happened
> is that asterisk informs the endpoint (through its own re-INVITE?)
> that of the new port/ip so that this endpoint could send to it
> directly, without asterisk sending to it first. Because asterisk did
> start sending to it itself, the relay locks in the source ip/port for
> this stream and will ignore other UDP traffic sent to this port.

It took me a few more test calls and a lot of crunch time to wrap my mind
around what you had said.

I believe I've finally found what you're talking about.  In another call, I
saw in a media capture the Asterisk box had "dribbled" about 8 RTP packets
to the new, post-reINVITE ip/port on the relay before its RTP stops and the
PSTN gateway's RTP starts.  But, as you've mentioned, by this time it's too
late because the relay has locked in the Asterisk box's IP/port and the PSTN
gateway RTP is ignored.  I imagine this is because of the processing lag in
the reinvite on the PSTN gateway-side of the Asterisk box.

> So in a sense it's asterisk that's confused by its own re-INVITE, not
> mediaproxy...

Yes.  Indeed it does.  Imagine that.

Thanks for your help.


- Jeff