First a general comment: It is not clear to me why this is a separate document and not part of draft-ietf-schc-architecture. draft-ietf-schc-architecture already specifies the use of a new ether type, protocol number, and port number, so the registration should be requested in that same document. At minimum this draft should have draft-ietf-schc-architecture as normative reference, and more important also the other way around, draft-ietf-schc-architecture needs to have this draft as a normative reference.

On the port request, the use case is not clear to me. The section on "Basic use case for SCHC as a UDP port number" is unfortunately empty. The document mentions firewall traversal as the use case. Please not that RFC6335, however, does not recommend to use ports for firewall rules. Further a firewall would usually restrict access based on application information, however, using a separate port for SCHC that then would carry different kind of application traffic which is not recognisable for the firewall would probably not help the firewall. Therefore it would probably more useful to use the same port number as the compressed packet to enable firewall traversal. But again, the use case is not described and not clear to me.

Further, as this kind of port usage is not recommended by RFC6335, I would recommend to request a review by the port registry expert team. But again, at the moment I do not see a use case and do not recommend to request a separate port number for SCHC.

Thanks for requesting the early review. I hope my input helps the working group process.