Re: [Gen-art] Gen-ART review of draft-ietf-mmusic-sdp-media-capabilities-15

[Flemming Andreasen <[e-mail]>]

Hi Alexey

Thank you for your review of the document - comments below:

On 11/26/12 7:03 AM, Alexey Melnikov wrote:
> I am the assigned Gen-ART reviewer for this draft. For background on
> Gen-ART, please see the FAQ at
>   <http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.
>
> Please resolve these comments along with any other Last Call comments
> you may receive.
>
> Document: draft-ietf-mmusic-sdp-media-capabilities-15
> Reviewer: Alexey Melnikov
> Review Date: 2012-11-26
> IETF LC End Date: 2012-11-12
> IESG Telechat date: not scheduled
>
> Summary:  This document is ready for publication as Proposed Standard,
> with nits.
>
> Nits/editorial comments:
>
> This might be obvious to a SIP implementer, but the media type/subtype 
> definition RFC is not referenced anywhere. Should it be?
>
I don't believe so. The document is an extension of SDP (RFC 4566) which 
maintains its own media type name space and registry and hence it simply 
follows the rules of SDP (as defined in RFC 4566, which did change from 
the old SDP spec defined in RFC 2327).

RFC 4288 (which I presume you are referring to here) should not apply.



> 3.3.5. The Latent Configuration Attribute
>
>    Latent configurations may be announced by use of the latent
>    configuration attribute, which is defined in a manner very similar to
>    the potential configuration attribute.  The latent configuration
>    attribute combines the properties of a media line and a potential
>    configuration.  The media type (mt=) and the transport protocol(s)
>    (t=) MUST be specified since the latent configuration is independent
>    of any media line present.  In most cases, the media configuration
>    (m=) parameter MUST be present as well (see Section 4 for examples).
>
> This doesn't look like a correct use of MUST, please reword not to use 
> any RFC 2119 keyword or at least provide a pointer to a document that 
> contains the original requirement.
How about this:
<quote>
           Latent configurations may be announced by use of the latent
           configuration attribute, which is defined in a manner very 
similar
           to the potential configuration attribute. The latent 
configuration
           attribute combines the properties of a media line and a potential
           configuration. A latent configuration MUST include a media 
type (mt=) and a transport protocol configuration parameter
       since the latent configuration is independent
           of any media line present. In most cases, the media configuration
           (m=) parameter needs to be present as well (see Section 4 for 
examples).
</quote>
>
>    The lcfg attribute is a media level attribute.
>
>  [...]
>
>    If a cryptographic attribute, such as the SDES "a=crypto:" attribute
>    [RFC4568], is referenced by a latent configuration through an acap
>    attribute, any keying material required in the conventional
>    attribute, such as the SDES key/salt string, MUST be included in
>    order to satisfy formatting rules for the attribute.  The actual
>    value(s) of the keying material SHOULD be meaningless, and the
>
> Can you please elaborate on what are you trying to say here?
>
Is this better:
<quote>
          If a cryptographic attribute, such as the SDES "a=crypto:"
           attribute [RFC4568], is referenced by a latent
           configuration through an acap attribute, any keying material
           required in the conventional attribute, such as the SDES key/salt
           string, MUST be included in order to satisfy formatting rules for
           the attribute. Since the keying material will be visible but 
not actually used at this stage (since it's a latent configuration),
       the value(s) of the keying material SHOULD be meaningless, and 
the receiver of the lcfg attribute
       MUST ignore the values.
</quote>

> receiver of the lcfg attribute MUST ignore the values.
> .
>

Thanks

-- Flemming