Subject: [MMUSIC] Fwd: Re: I-D Action:draft-loreto-mmusic-sctp-sdp-03.txt

From: "James M. Polk" <[email-masked]>
Date: Wed, 18 Mar 2009 13:47:52 -0500

I'm the TSVWG chair, where SCTP has been designed 
and developed over the years, and I saw the 
draft-loreto-mmusic-sctp-sdp-03 announcement and 
decided to ask the two main creators of SCTP and 
its extensions about how this ID, which I was not 
aware of previously, was up to task wrt SCTP. 
Below are the two responses I got from

         Randy Stewart <[email-masked]>
         Michael Tüxen <[email-masked]>

which recommend changes be made for this to move 
forward from an SCTP point of view. Neither Randy 
nor Michael are members of MMUSIC, but I have 
been for a while - so I'm the one to post this message on their behalf.

James

>Cc: "James M. Polk" <[email-masked]>
>From: Randy Stewart <[email-masked]>
>To: Michael Tüxen <[email-masked]>
>Subject: Re: I-D Action:draft-loreto-mmusic-sctp-sdp-03.txt
>Date: Wed, 18 Mar 2009 04:31:55 -0400
>
>Michael/James:
>
>I agree with Michael here.. they should at least include
>DTLS if not just get rid of TLS all-together.
>
>One other item that is an open issue is:
>
>OPEN ISSUE: that intermediaries such as SBCs will not be aware of some
>of the IP addresses used for media because they will not appear in the
>SDP. We can RECOMMEND that SCTP endpoints use a main address all the
>time (e.g., not to retransmit to a backup address) and that they send
>a re-INVITE every time they change that address. Alternatively (or
>additionally), we could add SDP attributes with all the IP addresses
>that can be used by the association.
>
>I would recommend they NOT do the re-invite and instead add the SDP
>attributes.
>For that matter an endpoint can use the socket API to get a list of
>all the peers addresses so this should not be too difficult .. i.e. they
>would not even have to pass it back and forth if they did not want
>too. If they do choose to give a list, they can get that too but
>SCTP stacks do use address scoping to determine which of
>the bound addresses can be sent to the peer... hmm I guess
>we should resurrect that draft :-)
>
>R
>
>On Mar 9, 2009, at 8:53 PM, Michael Tüxen wrote:
>
>>Hi James,
>>
>>I would recommend that the ID does not make use of TLS/SCTP
>>as described in RFC3436, since no one has implemented this
>>yet and it does not support PR-SCTP. I would assume that
>>for media transport, PR-SCTP is pretty useful. Instead DTLS/SCTP
>>as described in I-D.ietf-tsvwg-dtls-for-sctp should be used.
>>
>>Best regards
>>Michael
>>
>>
>>On Mar 10, 2009, at 12:27 AM, James M. Polk wrote:
>>
>>>At 06:25 PM 3/9/2009, Randy Stewart wrote:
>>>>nope.. had not seen it..
>>>>
>>>>But I will go read it now :-)
>>>
>>>thanks
>>>
>>>
>>>>R
>>>>On Mar 9, 2009, at 1:15 PM, James M. Polk wrote:
>>>>
>>>>>Randy/Michael
>>>>>
>>>>>Are either of you aware of this ID?
>>>>>
>>>>>Wondering if there might need to be a review by one/both of  you.
>>>>>It's only 8 pages, and it is about SCTP, so you might be
>>>>>interested.
>>>>>
>>>>>James
>>>>>
>>>>>>From: [email-masked]
>>>>>>To: [email-masked]
>>>>>>Subject: I-D Action:draft-loreto-mmusic-sctp-sdp-03.txt
>>>>>>Date: Mon,  9 Mar 2009 02:45:02 -0700 (PDT)
>>>>>>
>>>>>>A New Internet-Draft is available from the on-line Internet-Drafts
>>>>>>directories.
>>>>>>
>>>>>>      Title           : Stream Control Transmission Protocol
>>>>>>(SCTP)-Based Media Transport in the Session Description Protocol
>>>>>>(SDP)
>>>>>>      Author(s)       : S. Loreto, G. Camarillo
>>>>>>      Filename        : draft-loreto-mmusic-sctp-sdp-03.txt
>>>>>>      Pages           : 8
>>>>>>      Date            : 2009-03-09
>>>>>>
>>>>>>SCTP (Stream Control Transmission Protocol) is a transport
>>>>>>protocol
>>>>>>used to establish associations between two endpoints.  This
>>>>>>document
>>>>>>describes how to express media transport over SCTP in SDP (Session
>>>>>>Description Protocol).  This document defines the 'SCTP' and
>>>>>>'SCTP/
>>>>>>TLS' protocol identifiers for SDP.
>>>>>>
>>>>>>A URL for this Internet-Draft is:
>>>>>>http://www.ietf.org/internet-drafts/draft-loreto-mmusic-sctp-sdp-03.txt
>>>>>>
>>>>>>Internet-Drafts are also available by anonymous FTP at:
>>>>>>ftp://ftp.ietf.org/internet-drafts/
>>>>>>
>>>>>>Below is the data which will enable a MIME compliant mail reader
>>>>>>implementation to automatically retrieve the ASCII version of the
>>>>>>Internet-Draft.
>>>>>>
>>>>>>
>>>>>><ftp://ftp.ietf.org/internet-drafts/draft-loreto-mmusic-sctp-sdp-03.txt 
>>>>>>  >>>>> >
>>>>>>_______________________________________________
>>>>>>I-D-Announce mailing list
>>>>>>[email-masked]
>>>>>>https://www.ietf.org/mailman/listinfo/i-d-announce
>>>>>>Internet-Draft directories: http://www.ietf.org/shadow.html
>>>>>>or ftp://ftp.ietf.org/ietf/1shadow-sites.txt
>>>>
>>>>-----
>>>>Randall Stewart
>>>>[email-masked]
>>>>
>
>-----
>Randall Stewart
>[email-masked]
>
>