Hi,

Yes, I tried.

I had this code in my cfg file:

sdp_remove_media("video");
append_hf("P-hint: video removed\r\n");

rtpengine_offer("symetric direction=pub direction=priv codec-transcode=PCMU codec-transcode=PCMA codec-transcode=GSM codec-transcode=G729");

But when I check the INVITE going out from kamailio,

I see the P-hint header but the m=video line is still there in the SDP:

INVITE sip:user2@10.255.255.1997072 SIP/2.0
Max-Forwards: 70
Record-Route: <sip:192.168.2.198;lr=on;ftag=837235;vsf=AAAAAEVGVUMAcUVUQkUAbhcKHnQxLmNvbQ--;did=662.4f01>
To: <sip:05022222222@192.168.2.198>
From: 05011111111 <sip:05011111111@test1.com>;tag=837235
Call-ID: 368391
CSeq: 14806 INVITE
Content-Type: application/sdp
Contact: <sip:user1@192.168.2.50:7070>
User-Agent: Zoiper
Allow-Events: presence, kpml, talk
Via: SIP/2.0/UDP 192.168.2.198;branch=z9hG4bK82de.2d1517380038597f70a08f7217851c70.0
Via: SIP/2.0/UDP 10.255.255.199:7070;received=192.168.2.50;branch=z9hG4bK794289;rport=7070
Content-Length: 518
P-hint: video removed

v=0
v=0
o=71924084 8000 8001 IN IP4 192.168.2.110
s=SIP Call
c=IN IP4 192.168.2.198
t=0 0
m=audio 48882 RTP/AVP 0 8 3 18 101
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:3 GSM/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=no
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=sendrecv
a=rtcp:48883
a=ptime:20
m=video 48912 RTP/AVP 105
b=AS:704
a=rtcp-fb:* nack pli
a=rtcp-fb:* ccm fira=rtpmap:105 H264/90000
a=fmtp:105 profile-level-id=428016; packetization-mode=1
a=sendrecv
a=rtcp:48913

I also tried doing the removal after rtpengine_offer()/rtpengine_manage() but the same thing happens.

I also tried to use

msg_apply_changes();

with the same results.

So it seems rtpengine_offer() is executed later in the processing and over the original SDP.

Checking the docs what eventually worked was this:

# set rtpengine to read the body from an AVP:

modparam("rtpengine", "read_sdp_pv", "$avp(sdp)")

# set $avp(sdp) to a copy of $rb and replace the m=video line:

$avp(sdp) = $rb;

subst_attr("$sdp","/m=video [0-9]*/m=video 0/");

So rtpengine would operate on a

m=video 0 RTP/AVP XXX

line and so it would not set up rtp proxying for it.

Then the original SDP line:
m=video 10004 RTP/AVP 105
became this in the forwarded SDP:
m=video 0 RTP/AVP 0

Thanks.

On Thu, Aug 25, 2022 at 3:39 PM Henning Westerholt <hw@gilawa.com> wrote:

Hello,

already tried the sdpops module?

https://kamailio.org/docs/modules/5.5.x/modules/sdpops.html#sdpops.f.sdp_remove_media

Cheers,

Henning

--

Henning Westerholt – https://skalatan.de/blog/

Kamailio services – https://gilawa.com

From: sr-users <sr-users-bounces@lists.kamailio.org> On Behalf Of mayamatakeshi
Sent: Thursday, August 25, 2022 1:49 AM
To: Kamailio (SER) - Users Mailing List <sr-users@lists.kamailio.org>
Subject: [SR-Users] Disabling video rtp proxing

Hi,

I'm using rtpengine for RTP proxying with kamailio.

I use it just for audio.

But eventually some terminal reinvites offering video.

I don't want to refuse the request but just disable RTP proxying for video as my employer has limited bandwidth and want to reserve it only for audio.

So I checked the rtpengine module documentation but it seems there is no way to restrict RTP proxying to be performed only for m=audio.

I tried some things like

replace_body("^m=video [0-9]+", "m=video 0");

and
subst_body('/^m=video [0-9]+ /m=video 0 /');

and

msg_apply_changes();

but still the RTP proxying for video is set up.

Any hints on how to solve this?