Re: [AVTCORE] New Possible Errata in RFC2326 (And Draft) regarding Blocksize

[[e-mail] (Dale R. Worley)]

Julius Friedman <[e-mail]> writes:
> 18.10 <http://tools.ietf.org/html/draft-ietf-mmusic-rfc2326bis-40#section-18.10>.
> Blocksize
>
>    The Blocksize request-header field is sent from the client to the
>    media server asking the server for a particular media packet size.
>    This packet size does not include lower-layer headers such as IP,
>    UDP, or RTP.  The server is free to use a blocksize which is lower
>    than the one requested.  The server MAY truncate this packet size to
>    the closest multiple of the minimum, media-specific block size, or
>    override it with the media-specific size if necessary.  The block
>    size MUST be a positive decimal number, measured in octets.  The
>    server only returns an error (4xx) if the value is syntactically
>    invalid.
>
> Both paragraphs go to specify that the number MUST be positive but
> specify no LOWER bound.
>
> A Blocksize of 12 or less will cause data loss under UDP and cause
> invalid framing under TCP.

Could you explain this in more detail?  Since the "Blocksize" number
"does not include lower-layer headers such as IP, UDP, or RTP", it seems
to me that it counts only the bytes after the "RTP Fixed Header Fields"
and any RTP header extensions, and that number legitimately could be
small (depending on the media encoding in the RTP).

> It should be noted that the Blocksize MUST be a positive decimal
> number greater than or equal to that supported by the underlying
> transport.

In any case, *this* RFC does not *have* to state that, as that is a
requirement imposed by other RFCs. 

> I would like to file this errata as soon as possible if everyone agrees;
>
> If it's not erratum can we please also address this misnomer I seem to have.

As far as I can tell, it's not an erratum, because there is no "error"
in the RFC.  What you're suggesting is that there is useful information
that the RFC does not include, but that information is not an error in
this RFC's text.

Dale