Re: [Linphone-developers] sdp in re-invite rfc 3261 14.1. Current support/intentions?

[Simon Morlat]

Hi Dave,

Thanks for the detailed analysis.
My apologize, indeed the INVITE without SDP is something supported but not the 
RE-INVITE without SDP.
This is a feature which is lacking in linphone.
As it is lacking to few people it has never been developped.
Would you be interested in sending a patch for this ?

Simon

Le vendredi 17 juillet 2009 17:38:25, Dave Harley a écrit :
> Hi Simon,
>
> I managed to get a test preformed using the latest version of Linphone
> for windows (3.1.2).
> Hopefully this is up to date enough.
>
> Scenario:
> 1st test.
> 1) Linphone calls an analogue extension which is connected to a Mitel
> PABX.
> 2) Call is established.
> 3) Analogue extension tries to go on hold.
> 4) Analogue extension tries to retrieve call from hold.
> 5) Call is terminated ( actually not sure which end hangs up but its not
> important).
>
> 2nd test is the exact same with the exception that the call is made from
> a xlite client.
>
> Attached are wireshark pcap traces of the sip transfer for each test and
> the debug trace produced by the Linphone client.
>
> In the Linphone test the interesting bit is that Linphone issue's a 603
> decline to the bodyless (re-)invite which is received after the dialog
> has been established.
> In the 2nd test the xlite response to the same packet  is 200 Ok with an
> SDP body attached, which is acked with an SDP body ( including the hold
> indication) by the Mitel.
>
> The other interesting thing is that the Linphone test shows no
> indication of a off hold event, which makes sense cause it never went on
> hold in the first place I guess.
> The xlite does see the off hold (re-)invite.  However in this case the
> invite does have a body.  Screwy pabx!
>
> >From my reading of 3216 sec 14.1 I would think that xlite is more
>
> compliant, but I suppose I would say that. Certainly from an interop
> point of view it would be nice if Linphone handled the interaction
> similarly.
> I'm sure like all RFC's its open to interpretation and the xlite/Mitel
> interpretation might not match your own views.
>
> I'd be grateful if you could let me know your analysis.  If there is any
> further testing I can do let me know and I'll do by best.
>
> Best regards,
> Dave.
>
>
>
> The results are as follows:
>
> On Thu, 2009-07-16 at 17:25 +0200, Simon Morlat wrote:
> > Hi Dave,
> >
> > Receiving of INVITEs and reINVITEs without SDP is implemented and it
> > should work. I think it has been implemented shortly after the email you
> > refer. Try lastest release (3.1.2). This feature is not tested very
> > often, just tell me if you find a bug.
> >
> > Simon
> >
> > Le jeudi 16 juillet 2009 16:17:32, Dave Harley a écrit :
> > > Hi All,
> > >
> > > There was a query about 2 years ago regarding receiving invites and
> > > re-invites with no sdp offer when interoping with a mitel.  It
> > > referenced 14.1 and 13.2.1 of RFC 3261.
> > >
> > > I'm running an old release of linphone which was happily doing its job
> > > up to now.  However recently it appears that I need to support the
> > > above against both a Mitel and an Aastra A5000 iPBX.
> > >
> > > At the time Simon pointed out he had no immediate intention of
> > > implementing this (from the original thread:
> > > http://www.mail-archive.com/address@hidden/msg01282.html ).
> > > Just wondering has this situation changed?  Is there any support in the
> > > top of the tree for this aspect of the RFC?
> > >
> > > I would test this myself before asking but getting access to the
> > > environment where it exhibits is... problematic.
> > >
> > > BTW I originally thought this was an osip issue and posted there. I was
> > > wrong and was, very helpfully, pointed in the right direction. So
> > > apologies if this mail seems familiar to any list members.
> > >
> > > Best regards,
> > > Dave
>
> Dave Harley.Senior Systems Engineer
>
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