[Replies to the MMUSIC list only please, since this is an SDP issue] On 13 Sep 2004, at 16:27, Even, Roni wrote:
Reading the document and looking at the IANA database I noticed that the media types do not include “data” and “control”.
The current SDP draft has in section 9 9.2.1 Media types ("media") The set of media types is intended to be small and SHOULD NOT be extended except under rare circumstances. The same rules should apply for media names as for top-level MIME content types, and where possible the same name should be registered for SDP as for MIME. For media other than existing MIME top-level content types, a standards-track RFC MUST be produced for a new top-level content type to be registered, and the registration MUST provide good justification why no existing media name is appropriate (the "Standards Action" policy of RFC 2434 [5]. This memo registers the media types "audio", "video", "text", "application", "data" and "control". So does it mean that in an RTP payload specification I will register a payload type as application and use in SDP m line as data?
No. The "data" and "control" types are somewhat under-specified in SDP, but are intended to be used as alternatives to the other top-level media types. We should probably either remove them in favour of "application", or define new top-level MIME types if there's a need. Using "application" as the MIME type and "m=control" or "m=data" in SDP is wrong, though. The simplest solution is to remove these in the next revision of sdp-new, and for them to be registered if there's a need later (unless someone is willing to contribute text to fix sdp-new). Colin