Your environment.

• Version: v4.1.1
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• Other Information: -

What did you do?

I'm using a python WebRTC client written using aiortc/aiortc to connect to a pion SFU. I noticed that the TrackID parsing from the SDP in aiortc was failing because of the MSID semantic used in the SDP generated by pion. Specifically, pion is generating an SDP with a=msid-semantic:WMS* whereas aiortc expects it to be a=msid-semantic:WMS * (with a space between WMS and *).

Here's the relevant section from the RFC -

The name of the attribute is "msid-semantic".

   The value of the attribute is given by the following ABNF:

     msid-semantic-value = msid-semantic msid-list
     msid-semantic = token ; see [RFC 4566](https://datatracker.ietf.org/doc/html/rfc4566)
     msid-list = *(" " msid-id) / " *"

What did you expect?

Expected a=msid-semantic:WMS * in the SDP

What happened?

Got a=msid-semantic:WMS* in the SDP