[SR-Users] 488 Not Acceptable Here when remove codecs with rtcp-fb

[José Lopes]

Hello,

I am sending in attach a pcap with a call between two webrtc clients, that
reproduces this scenario.
I am using as example the configuration at
https://github.com/havfo/WEBRTC-to-SIP .
I apply this change on the kamailio configuration to reproduce this
scenario:

@@ -350,6 +350,8 @@ request_route {
        # authentication
        route(AUTH);

+  sdp_keep_codecs_by_name("VP8","video");
+  msg_apply_changes();
        # record routing for dialog forming requests (in case they are
routed)
        # - remove preloaded route headers
        remove_hf("Route");

Without this change, I can make calls between two webrtc clients.

Thanks for your help, so far.

Best regards,
Jose Lopes




On Mon, May 11, 2020 at 10:21 AM José Lopes <jose.lopes at itcenter.com.pt>
wrote:

> Hello,
>
> Sorry, I forgot to mention that, between the call of the two webrtc
> clients, there is a B2BUA that only supports SIP UDP and RTP, so I need to
> use rtpengine to translate from DTLS/SRTP to RTP.
> I will try to make a call between the two webrtc clients and only use
> kamailio without rtpengine to limit the issue.
>
> Os melhores cumprimentos / Best regards,
>
> *José Lopes*
> Research and Development Technician
>
> Phone: +351 256 370 980
> Email: jose.lopes at itcenter.com.pt
>
>
> On Tue, May 5, 2020 at 5:15 PM Juha Heinanen <jh at tutpro.com> wrote:
>
>> This 488 think reminds me that SIP over webrtc is broken.
>>
>> Webrtc UAS (at least JsSIP) cannot issue 488 before the UAS has started
>> to ring.  It is very frustrating for the callee to get such a spam ring.
>>
>> RFC3261 section "8.2 UAS Behavior" tells:
>>
>>    Note that request processing is atomic.  If a request is accepted,
>>    all state changes associated with it MUST be performed.  If it is
>>    rejected, all state changes MUST NOT be performed.
>>
>> So it is against the standard to issue 180 and after that reject the
>> request with 488.
>>
>> -- Juha
>>
>> _______________________________________________
>> Kamailio (SER) - Users Mailing List
>> sr-users at lists.kamailio.org
>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.kamailio.org/pipermail/sr-users/attachments/20200511/28c76b19/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Zlk2u0KrhbeJJ0F69FYWe5Plv.pcap
Type: application/vnd.tcpdump.pcap
Size: 33722 bytes
Desc: not available
URL: <http://lists.kamailio.org/pipermail/sr-users/attachments/20200511/28c76b19/attachment.pcap>