[AVT] draft-ietf-avt-rtp-vorbis: configuration-uri

[Peter Saint-Andre <stpeter at jabber.org>]

In draft-ietf-avt-rtp-vorbis-05 we find:

      configuration-uri:  the URI of the configuration headers in case
         of out of band transmission.  In the form of
         "protocol://path/to/resource/".

This assumes that URIs have a certain structure and that there is a 
resource with a certain media type available at the URI. While that is 
true of many URI schemes (e.g., http: and rtsp:), it is not true of 
other URI schemes (e.g., mailto: and xmpp:). Unless you have a good 
reason for thinking that a configuration-uri must be of the form you 
specify, I think it would be best to generalize the format so that any 
URI that conforms to RFC 3986 can be used.

As an example, we might define a way to retrieve configuration headers 
via XMPP, for which the URI might be something like this:

xmpp:user at example.com?config;header=resource

The spec goes on to say:

                                          Depending on the specific
         method, a single configuration packet could be retrived by its
         number, or multiple packets could be aggregated in a single
         stream.  Such aggregates MAY be compressed using either bzip2
         [15] or gzip [13].  A sha1 [9] checksum MAY be provided for
         aggregates.  In this latter case the URI will end with the
         aggregate name, followed by its compressed extension if
         applies, a "!" and the base64 [8] representation of the
         sha1hash of the above mentioned compressed aggregated as in:
         "protocol://path/to/resource/aggregated.bz2!sha1hash".  The
         trailing '/' discriminates which of two methods are in use.  It
         MUST follow the associated delivery method parameter (either
         "in_band" or "out_band").

Do you mean that if the URI ends with a trailing slash, then the method 
in use is "simple configuration packet" but if the URI does not end in a 
trailing slash then the method in use is "multiple packets aggregated in 
a single stream"? Again, this seems limited to a specific URI structure, 
since in the XMPP example above we might do something like the following 
for multiple aggregated packets:

xmpp:user at example.com?config;header=resource;aggregate=aggregated.bz2;hash=sha1hash

Finally, must the configuration-uri be a URI or may it be an IRI?

Peter

--
Peter Saint-Andre
XMPP Standards Foundation
http://www.xmpp.org/xsf/people/stpeter.shtml

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