Re: [Linphone-users] lastest update breaks dtmf on ios and android

[Gautier Pelloux-Prayer]

Hi Russell,

Sorry for the late answer we were quite busy these last days.

The issue is indeed caused by some changes in our code which was necessary to 
be RFC compliant:

1) According to RFC4733, telephony-event clock-rate should be the same as audio 
codec in use (https://tools.ietf.org/html/rfc4733#section-2.1). Since you are 
using Opus 48kHz, Linphone offers telephone-event/48000 (among with others).
2) Freeswitch is declining it (this payload type is not included in the answer 
from Freeswitch). Linphone is then not allowed to send telephone-event/48000 
according to offer answer model (RFC3264, Section 7). Since sending 
telephone-event/8000 over a 48000 Hz audio stream is also prohibited, no 
telephone-event are sent at all.

I think you should consider reporting this issue to Freeswitch project.

Cheers,
 
Gautier Pelloux-Prayer
Software Engineer @ Belledonne Communications

> On 12 May 2015, at 19:10, Russell Treleaven <address@hidden> wrote:
> 
> I did a bit more testing and have more findings to share.
> 
> Until the latest update to the linphone mobile clients rfc-2833 and opus 
> working as expected with freeswitch
> 
> ios Linphone iPhone 2.2.4.2-store-85-gbfcbadb
> android Linphone 2.4.0
> 
> The simplest change to make rfc-2833 dtmf work again is to disable opus on 
> linphone
> 
> Linphone is the uac and freeswitch is the uas in the described scenario
> 
> the relevant bits of the bad sdp exchange looks like this
> 
> invite
>    m=audio 7076 RTP/AVP 96 0 8 9 101 97
>    a=rtpmap:96 opus/48000/2
>    a=fmtp:96 useinbandfec=1; stereo=0; sprop-stereo=0
>    a=rtpmap:101 telephone-event/48000
>    a=rtpmap:97 telephone-event/8000
>    
> ok
>    m=audio 16016 RTP/AVP 96 101
>    a=rtpmap:96 opus/48000/2
>    a=fmtp:96 useinbandfec=1
>    a=rtpmap:101 telephone-event/8000
>    a=fmtp:101 0-16
> 
> the relevant bits of good sdp exchange looks like this
> 
> invite
>    m=audio 7076 RTP/AVP 0 8 101
>    a=rtpmap:101 telephone-event/8000
> 
> ok
>    m=audio 16008 RTP/AVP 0 101
>    a=rtpmap:0 PCMU/8000
>    a=rtpmap:101 telephone-event/8000
>    a=fmtp:101 0-16
> 
> Can you confirm that the last update to linphone changed your spd offer in 
> regard to opus and dtmf?
> 
> Sincerely,
> 
> Russell Treleaven
> 
> 
> On Tue, May 12, 2015 at 1:32 AM, Russell Treleaven <address@hidden> wrote:
> Actually info is working, using it as a partial workaround for now.
> 
> 
> On Mon, May 11, 2015 at 2:26 PM, Russell Treleaven <address@hidden> wrote:
> Hi,
> 
> I am calling an ivr on 
> FreeSWITCH Version 1.5.15b+git~20141215T224714Z~0b414a8de8~64bit (git 0b414a8 
> 2014-12-15 22:47:14Z 64bit)
> 
> Linphone was working as expected until I updated the apps to the latest 
> release.
> Acrobits, Bria and Zoiper all work as expected.
> I have included a couple of sample invites and a small dialplan exerpt that 
> demonstrates the problem.
> 
> The rtpmap for linphone has the sample rate set to 48000 which may be an 
> issue.
> 
> 
> 
> 
> 
> On Mon, May 11, 2015 at 5:33 AM, Gautier Pelloux-Prayer <address@hidden> 
> wrote:
> Hi,
> 
> Testing it between:
> - Linphone Android 2.4.0 and Linphone desktop (both SIP INFO + RFC2833): 
> working fine.
> - Linphone Android 2.4.0 and tier SIP provider (RFC2833): working fine.
> - Linphone iphone 2.2.5-125 and Linphone desktop (both SIP INFO + RFC2833): 
> working fine.
> 
> What's your setup?
> 
> Regards,
> 
> Gautier Pelloux-Prayer
> Software Engineer @ Belledonne Communications
> 
> > On 08 May 2015, at 03:55, Russell Treleaven <address@hidden> wrote:
> >
> > Can someone please verify that the latest update to Android and IOS 
> > linphone applications breaks DTMF. Neither info or rfc-2833 seem to work.
> >
> > versions tested
> > ios Linphone iPhone 2.2.4.2-store-85-gbfcbadb
> > android Linphone 2.4.0
> >
> > Sincerely
> >
> > Russell Treleaven
> > _______________________________________________
> > Linphone-users mailing list
> > address@hidden
> > https://lists.nongnu.org/mailman/listinfo/linphone-users
> 
> 
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