SSRC optional SDP field not being handled correctly

[marcMLS]

Hi team,

I noticed that when using certain softphones, the engine fails to parse the incoming SDP because of strict SSRC handling. For example, an SDP line like:

a=ssrc:2330119309

causes a ValueError: not enough values to unpack (expected 2, got 1) in aiortc, because the code expects both an SSRC value and a description separated by a space.

This prevents the engine from handling calls from softphones that do not include the optional SSRC description.

Suggested improvement:

• Make the SSRC parsing more robust by accepting lines with only the SSRC value.
• Optionally, fall back gracefully when no description is present.

This would improve compatibility with a wider range of SIP endpoints and softphones.

Thanks!