Duplicated Payload Type number in SDP

[Francisco Franco Gallego]

Hi,

We detected the KMS fails when a PT number is duplicated in the audio and in the video codec lists.

The issue is exactly the same that this thread https://groups.google.com/g/kurento/c/ql-rNjKX73M/m/Ee0K3mOJDAAJ

This is the SDP section:

m=audio 48792 RTP/AVP 96 101
a=rtpmap:96 opus/48000/2
a=rtpmap:101 telephone-event/48000

m=video 36548 RTP/AVP 96 97

a=rtpmap:96 VP8/90000
a=rtpmap:97 H264/90000

After reading this section in RFC3551 https://tools.ietf.org/html/rfc3551#section-6

| Payload types of different media types SHALL NOT be interleaved or
| multiplexed within a single RTP session unless [RFC8860] is used
| and the application conforms to the applicability constraints.
| Multiple RTP sessions MAY be used in parallel to send multiple
| media types.

The payload type will inform a receiver which
media type the SSRC is being used for. Thus, the payload type MUST
be unique across all of the payload configurations, independent of
the media type that is used in the RTP session.

It makes clear that this is not allowed but using this bad SDP causes KMS freezing and we must restart KSS to re-establish the service.

There is something we can do to manage that in KSS and avoid KMS freezing? Should I open an issue in the bug tracker?

Regards

Fran