[MMUSIC] Re: ADs - Re: Status of draft-ietf-mmusic-sdescriptions-12.txt?

[Mark Baugher <[e-mail]>]

Hello,

An issue arose during RFC Editor review of draft-ietf-mmusic- 
sdescriptions-12 just prior to publication.  An Internet Draft  
document, Security Preconditions, appears among the Normative  
references.  The authors did not intend for it to be a Normative  
reference; it should have been in the Informative References  
section.  Still, this triggered a review and discussion.  Before  
proceeding to publication, the chairs and ADs wish for the WG to  
consider some of the issues of publishing draft-ietf-mmusic- 
sdescriptions without Security Preconditions.

SDP security descriptions (sdesc) as defined in draft-ietf-mmusic- 
sdescriptions-12.txt is designed to support a variety of signaling  
protocols that use SDP.  One of the most important is SIP. The way  
sdesc is defined, an answer has to be received before incoming media  
can be processed correctly by the offerer; this is unavoidable in  
cases where there are multiple crypto suites among the SDP offers.   
Without the answer, there is no way to determine which crypto offer  
has been selected by an answerer that sends media upon receiving the  
first SDP message.  This is a problem whenever media commences prior  
to receipt of the SDP answer.

The authors recognized this problem while working on the sdesc  
specification, and as a result, two of the authors wrote Security  
Preconditions (see draft-ietf-mmusic-securityprecondition-01.txt).  
However not everyone in the SIP community likes preconditions due to  
the added state machine complexity and signaling latency.  The  
current sdesc merely offers security preconditions as one possible  
solution, however it incorrectly lists it as a Normative reference.  
One alternative has already been offered (draft-wing-mmusic-sdes- 
early-media-00.txt) and at least one more extension to sdesc to  
address these issues is in the works.

  In lieu of the above, the authors would like to change the current  
Normative reference to security preconditions to be an Informative  
reference instead. There is a concern, however, that with such a  
change, we would not have a complete normative solution for SIP.  So,  
we're asking the WG members for comments.  draft-ietf-mmusic- 
sdescriptions-12.txt has finished last call in the WG and the IESG,  
but the document that completed last call relied upon security  
preconditions, which may not be the ultimate solution.  We would like  
to know if anyone in the WG objects to progressing this I-D without  
security preconditions being normative and without another normative  
solution to address the above issues. If you object, please speak up  
and let us know what the normative solution should be.

Thanks,

Mark, Flemming & Dan

_______________________________________________
mmusic mailing list
[e-mail]
https://www1.ietf.org/mailman/listinfo/mmusic