[OpenSIPS-Users] Invalid SDP Descriptor

Donat Zenichev donat.zenichev at gmail.com
Tue Mar 9 09:42:23 EST 2021

Good day Bullehs.

First of all I would like to mention that I don't have much experience with
But since of the absence of any possible answer, I will try to assist with
that, and might extend personal knowledge at the same time.

The response: "399 Bad SDP Invalid SDP Descriptor" is interpreted and shown
by your pj sip client I think.
And seems the issue happens when UAC (pjsip) receives the early-dialog
(183) or eventual (200 OK) response, which has an SDP answer.

We have a description of "PJMEDIA_SDP_EINSDP" here:
But unfortunately it's not that much descriptive.

Have you tried to dump the signaling traffic at both UAC side and UAS side
of the call?
If so, which final response is provided by UAS (OpenSIPS)? Is that the
error code of 3XX class from the very beginning?

What OpenSIPS/RTPproxy says in the appropriate log? (opensips.log and
rtpproxy.log, or the syslog if you haven't defined separate log files).
If you don't see anything in particular, then try to increase the debug

Other than that, have you tried to investigate the issue at your PJSIP
client using the web console?
Sometimes that can be quite useful and say what particularly PJSIP client
does not like at the moment. Errors should even be underlined with a red
color (depends on browser).

To me personally, it looks like PJSIP does not have any socket descriptor
to use, in order to reach the contact address provided by UAS (in either
183 or 200OK).
But, this is just my assumption and might have nothing to do with the

Also I would advise you to use this article provided by OpenSIPS dev team:
It's written for usage with 2.4 branch of the OpenSIPS, but might as well
work out good for 3.0.

Other than that 3.0 is no longer considered as a stable release, current
stable releases are 3.1.1 LTS and 2.4.9 LTS.
Please take this into account.

And have a nice day!

On Mon, Mar 8, 2021 at 1:04 PM HS <bullehs at gmail.com> wrote:

> Hi all.
> I am using Opensips (3.0) on Amazon EC2 and have implemented RTPProxy and
> it seems to do NAT Traversal fine. I am now trying to setup Active SIPREC
> recording and get the following error when I try and make calls:
> Bad SDP 399.. "Invalid SDP Descriptor (PJMEDIA_SDP_EINSDP).
> I think there's something wrong with my Opensips config - any suggestions
> please?
> Thanks.
> _______________________________________________
> Users mailing list
> Users at lists.opensips.org
> http://lists.opensips.org/cgi-bin/mailman/listinfo/users


Best regards,
Donat Zenichev
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