Subject: [MMUSIC] Feedback requested on requirements

From: [email-masked] (Dale R. Worley)
Date: Wed, 3 Apr 2013 22:05:07 -0400 (EDT)

DES F4  Multiple separate bundles within one SDP must be supported.

   DES F5  Bundles may contain other bundles as constituents.

   Of course, no bundle may directly or indirectly contain itself.  (I
   don't expect any current implementation to implement bundles within
   bundles, but we should design the mechanism to allow this, as some
   day we will likely need it.)

   DES F6  A bundle may contain zero constituents.

   A bundle with no constituents serves no purpose for the transport of
   media, but we are likely to someday need to describe such a bundle.
   (Compare that an SDP m= line is syntactically constrained to specify
   at least one payload type.  When SDP was used only to specify
   multicast sessions, this constraint was common sense.  But once SDP
   offer/answer was invented, when a media description was rejected, the
   natural representation would be an m= line with a zero port and no
   payload types.  But a payload type was syntactically required, so we
   now have to provide at least one token payload type in rejected m=
   lines.)

Dale