Not handling SCTP ParamType 32769 about webrtc HOT 3 CLOSED

Thanks for the ticket @daweifeng!

We need to get pion/sctp#284 merged. I will review

If you are interested @daweifeng I would appreciate your help reviewing the PR :)

from webrtc.

Thank you! The PR fixes my issue. I will take a look at the PR as well!

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@Sean-Der This has been marked as completed but the corresponding PR is not merged. The bug is still present and is breaking compatibility between pion and libdatachannel 0.20.

As discussed in paullouisageneau/libdatachannel#1030 (comment), the actual issue is not that parameter type 0x8001 is not handled (which is implemented by pion/sctp#284), it's that unmarshalling in pion seemingly fails on all unhandled parameters.

An SCTP endpoint does not need to support Zero Checksum Acceptable extension to connect with an endpoint that does. According to RFC 9260 that the endpoint behavior must depend on the highest-order two bits of the parameter type. Here it's 10, so the endpoint must skip the parameter and continue to process other parameters if it doesn't know it. Failing on unknown parameters breaks if peers attempt to negotiate SCTP extensions.

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