[Freeswitch-users] Multiple 183 SDP Change Codecs - allowed?

Avi Marcus avi at avimarcus.net
Tue Jul 3 23:21:55 MSD 2012


So with NDLB-allow-nondup-sdp does that mean when the first SDP chooses
PCMA then the second SDP with PCMU comes in - FS will still have that
option available? (http://pastebin.freeswitch.org/19423 shows that
currently it got lost after the 1st negotiation)

This was a parallel dial - the remote opensips apparently was trying
various gateways, though..

-Avi


On Tue, Jul 3, 2012 at 9:48 PM, Kristian Kielhofner <kris at kriskinc.com>wrote:

> If we only we had absolutes that were that simple...
>
> The default setting in FreeSWITCH when forking (parallel or serial) is
> to consider the first bridge (leg) that returns media (of any sort) as
> successful.  This FreeSWITCH behavior can be changed.  Many other
> implementations behave differently.
>
> In SIP (especially with proxies) this isn't an absolute and several
> other scenarios are still valid.  A leg can return 183 w/SDP and then
> a 4xx/5xx/6xx, which should then defer to another leg (or pass the
> error, or branch further, etc).  Various scenarios are perfectly valid
> per the specs.  It's up to the implementor/application to decide which
> behavior is preferred.
>
> On Tue, Jul 3, 2012 at 1:50 PM, Steven Ayre <steveayre at gmail.com> wrote:
> > 18x messages are supposed to make the call unreroutable since they
> indicate
> > the call has been successful on that route.
> >
> > -Steve
> >
> >
> >
> > On 3 July 2012 16:56, Avi Marcus <avi at avimarcus.net> wrote:
> >>
> >> They said the 1st carrier rejected it so the second 183 is from a second
> >> carrier.. but yes, the first carrier shouldn't be sending a 183...
> >> Anyway -- if you please look at the pcap from the first email, the log I
> >> posted a link to later, or the past two emails -- you'll see FS
> originally
> >> offers both PCMU and PCMA in the initial invite.
> >>
> >> I think we need Anthony to chime in here... he knows the RFC stuff!
> >>
> >> -Avi
> >>
> >>
> >>
> >> On Tue, Jul 3, 2012 at 6:22 PM, Kristian Kielhofner <kris at kriskinc.com>
> >> wrote:
> >>>
> >>> That's pretty nasty of voxbeam to do...  Considering they return the
> >>> first 183 less than one second after the initial INVITE I'd say it's
> >>> very likely they're providing false ringback and/or FAS (false answer
> >>> supervision).  Meanwhile the actual ringback comes over two seconds
> >>> later with PCMA.  That's shady and if I were you I'd switch carriers
> >>> just on principle.
> >>>
> >>> However, as I said before they're not doing anything that's not
> >>> allowed by the various specifications although FAS is considered by
> >>> many as fraud.
> >>>
> >>> What are your codec settings like?  Perhaps FS is rejecting PCMA
> >>> because you're not allowing it?
> >>>
> >>> On Tue, Jul 3, 2012 at 9:38 AM, Avi Marcus <avi at avimarcus.net> wrote:
> >>> > If so.. which I think is not.. is this a bug then in FS?
> >>> >
> >>> > http://pastebin.freeswitch.org/19423
> >>> > You see from the first SDP that PCMU and PCMA were both options.
> >>> > Then for the next SDP FreeSWITCH was only considering PCMU which was
> >>> > the one
> >>> > that got chosen by the first SDP.
> >>> >
> >>> > Voxbeam claims it's not their fault.. is it?
> >>> >
> >>> > -Avi
> >>> >
> >>> >
> >>> >
> >>> > On Tue, Jul 3, 2012 at 4:26 PM, Kristian Kielhofner <
> kris at kriskinc.com>
> >>> > wrote:
> >>> >>
> >>> >> Avi,
> >>> >>
> >>> >>   Multiple 18x responses that change the SDP are allowed.  I can't
> >>> >> find the specific document text now but as a random guy on the
> >>> >> internet (for whatever that's worth) I'm certain it is allowed.
> >>> >>
> >>> >>   A re-INVITE can't be sent from either side until the dialog has
> been
> >>> >> established (200+ACK).  In a case where the UAC (caller) would like
> to
> >>> >> update the session before it is established method UPDATE must be
> >>> >> used.
> >>> >>
> >>> >> On Tue, Jul 3, 2012 at 1:04 AM, Avi Marcus <avi at avimarcus.net>
> wrote:
> >>> >> > Are multiple 183s from the endpoint that changes the SDP allowed?
> >>> >> > I'm
> >>> >> > under
> >>> >> > the impression this is broken, similar to
> >>> >> > http://wiki.freeswitch.org/wiki/NDLB#NDLB-allow-nondup-sdp
> >>> >> > ... which is why when the codec changes, FS freaks out and cancels
> >>> >> > the
> >>> >> > call
> >>> >> > because of codec negotiation error.
> >>> >> > Does that NDLB flag allow this, too?
> >>> >> >
> >>> >> > First has: audio 10116 RTP/AVP 0 101 13
> >>> >> > Second has:  audio 49020 RTP/AVP 8 13 101
> >>> >> > PCAP: http://ge.tt/7MpyBwJ
> >>> >> >
> >>> >> > Can someone point me to the specific RFC so I can tell the
> supplier
> >>> >> > to
> >>> >> > fix
> >>> >> > it?
> >>> >> > And just curious.. what would make this allowed? A re-INVITE..?
> >>> >> >
> >>> >> > -Avi
> >>> >> >
> >>> >> >
> >>> >> >
> >>> >> >
> _________________________________________________________________________
> >>> >> > Professional FreeSWITCH Consulting Services:
> >>> >> > consulting at freeswitch.org
> >>> >> > http://www.freeswitchsolutions.com
> >>> >> >
> >>> >> > 
> >>> >> > 
> >>> >> >
> >>> >> > Official FreeSWITCH Sites
> >>> >> > http://www.freeswitch.org
> >>> >> > http://wiki.freeswitch.org
> >>> >> > http://www.cluecon.com
> >>> >> >
> >>> >> > Join Us At ClueCon - Aug 7-9, 2012
> >>> >> >
> >>> >> > FreeSWITCH-users mailing list
> >>> >> > FreeSWITCH-users at lists.freeswitch.org
> >>> >> > http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >>> >> >
> >>> >> > UNSUBSCRIBE:
> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >>> >> > http://www.freeswitch.org
> >>> >> >
> >>> >>
> >>> >>
> >>> >>
> >>> >> --
> >>> >> Kristian Kielhofner
> >>> >>
> >>> >>
> >>> >>
> _________________________________________________________________________
> >>> >> Professional FreeSWITCH Consulting Services:
> >>> >> consulting at freeswitch.org
> >>> >> http://www.freeswitchsolutions.com
> >>> >>
> >>> >> 
> >>> >> 
> >>> >>
> >>> >> Official FreeSWITCH Sites
> >>> >> http://www.freeswitch.org
> >>> >> http://wiki.freeswitch.org
> >>> >> http://www.cluecon.com
> >>> >>
> >>> >> Join Us At ClueCon - Aug 7-9, 2012
> >>> >>
> >>> >> FreeSWITCH-users mailing list
> >>> >> FreeSWITCH-users at lists.freeswitch.org
> >>> >> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >>> >>
> >>> >> UNSUBSCRIBE:
> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >>> >> http://www.freeswitch.org
> >>> >
> >>> >
> >>> >
> >>> >
> >>> >
> _________________________________________________________________________
> >>> > Professional FreeSWITCH Consulting Services:
> >>> > consulting at freeswitch.org
> >>> > http://www.freeswitchsolutions.com
> >>> >
> >>> > 
> >>> > 
> >>> >
> >>> > Official FreeSWITCH Sites
> >>> > http://www.freeswitch.org
> >>> > http://wiki.freeswitch.org
> >>> > http://www.cluecon.com
> >>> >
> >>> > Join Us At ClueCon - Aug 7-9, 2012
> >>> >
> >>> > FreeSWITCH-users mailing list
> >>> > FreeSWITCH-users at lists.freeswitch.org
> >>> > http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >>> >
> >>> > UNSUBSCRIBE:
> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >>> > http://www.freeswitch.org
> >>> >
> >>>
> >>>
> >>>
> >>> --
> >>> Kristian Kielhofner
> >>>
> >>>
> _________________________________________________________________________
> >>> Professional FreeSWITCH Consulting Services:
> >>> consulting at freeswitch.org
> >>> http://www.freeswitchsolutions.com
> >>>
> >>> 
> >>> 
> >>>
> >>> Official FreeSWITCH Sites
> >>> http://www.freeswitch.org
> >>> http://wiki.freeswitch.org
> >>> http://www.cluecon.com
> >>>
> >>> Join Us At ClueCon - Aug 7-9, 2012
> >>>
> >>> FreeSWITCH-users mailing list
> >>> FreeSWITCH-users at lists.freeswitch.org
> >>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >>> UNSUBSCRIBE:
> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >>> http://www.freeswitch.org
> >>
> >>
> >>
> >>
> _________________________________________________________________________
> >> Professional FreeSWITCH Consulting Services:
> >> consulting at freeswitch.org
> >> http://www.freeswitchsolutions.com
> >>
> >> 
> >> 
> >>
> >> Official FreeSWITCH Sites
> >> http://www.freeswitch.org
> >> http://wiki.freeswitch.org
> >> http://www.cluecon.com
> >>
> >> Join Us At ClueCon - Aug 7-9, 2012
> >>
> >> FreeSWITCH-users mailing list
> >> FreeSWITCH-users at lists.freeswitch.org
> >> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >> UNSUBSCRIBE:
> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >> http://www.freeswitch.org
> >>
> >
> >
> > _________________________________________________________________________
> > Professional FreeSWITCH Consulting Services:
> > consulting at freeswitch.org
> > http://www.freeswitchsolutions.com
> >
> > 
> > 
> >
> > Official FreeSWITCH Sites
> > http://www.freeswitch.org
> > http://wiki.freeswitch.org
> > http://www.cluecon.com
> >
> > Join Us At ClueCon - Aug 7-9, 2012
> >
> > FreeSWITCH-users mailing list
> > FreeSWITCH-users at lists.freeswitch.org
> > http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> > UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> > http://www.freeswitch.org
> >
>
>
>
> --
> Kristian Kielhofner
>
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:
> consulting at freeswitch.org
> http://www.freeswitchsolutions.com
>
> 
> 
>
> Official FreeSWITCH Sites
> http://www.freeswitch.org
> http://wiki.freeswitch.org
> http://www.cluecon.com
>
> Join Us At ClueCon - Aug 7-9, 2012
>
> FreeSWITCH-users mailing list
> FreeSWITCH-users at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freeswitch.org/pipermail/freeswitch-users/attachments/20120703/607aa2e9/attachment-0001.html 


Join us at ClueCon 2011 Aug 9-11, 2011
More information about the FreeSWITCH-users mailing list