Subject: [Simple] I-D Action:draft-ietf-simple-msrp-acm-06.txt

From: [email-masked]
Date: Fri, 5 Mar 2010 14:45:02 -0800 (PST)

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the SIP for Instant Messaging and Presence Leveraging Extensions Working Group of the IETF.

	Title           : An Alternative Connection Model for the Message Session Relay Protocol (MSRP)
	Author(s)       : C. Holmberg, S. Blau
	Filename        : draft-ietf-simple-msrp-acm-06.txt
	Pages           : 9
	Date            : 2010-03-05

This document defines an alternative connection model for Message
Session Relay Protocol (MSRP) User Agents (UAs), which uses the
connection-oriended media (COMEDIA) mechanism in order to create the
MSRP transport connection.  The model allows MSRP UAs behind Network
Address Translators (NATs) to negotiate which UA will initiate the
establishment of the TCP connection, in order for MSRP messages to
traverse the NAT.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-simple-msrp-acm-06.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.

---

From: nagesh kumar <[email-masked]>
Date: Wed, 10 Mar 2010 22:19:59 +0530

Hi Experts,

I am new to MSRP and plesae excuse me if this is a basic question.

For MSRP over TCP, the ACM draft seems to suggest that the mentioned
procedures can be used. But for MSRP over TLS, the section 4.3 says that the
UA MUST use the TLS mechanisms defined in [RFC4975] and [RFC4976].

Does this mean that MSRP relay has to be used if TLS were to be used? Why
can't ACM be used for NAT traversal for TLS connections like TCP?

Regards
Nagesh
On Sat, Mar 6, 2010 at 4:15 AM, <[email-masked]> wrote:

> This draft is a work item of the SIP for Instant Messaging and Presence
> Leveraging Extensions Working Group of the IETF.
>
>
> _______________________________________________
> Simple mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/simple
>
>

---

From: Ben Campbell <[email-masked]>
Date: Wed, 10 Mar 2010 11:01:05 -0600

<as-individual>

On Mar 10, 2010, at 10:49 AM, nagesh kumar wrote:

> For MSRP over TCP, the ACM draft seems to suggest that the mentioned procedures can be used. But for MSRP over TLS, the section 4.3 says that the UA MUST use the TLS mechanisms defined in [RFC4975] and [RFC4976].
>  
> Does this mean that MSRP relay has to be used if TLS were to be used? Why can't ACM be used for NAT traversal for TLS connections like TCP?
> 
> 

I interpreted that to mean that you use the TLS mechanisms defined in the base protocols. It isn't intended to require you to use relays if you weren't already using them--just to say that, if you use relays, you must follow the TLS rules for relays.

Perhaps it could be clarified with something like "...defined in [RFC4975], and if MSRP Relays are used, in [RFC4976]." 

Christer, thoughts?

---

From: nagesh kumar <[email-masked]>
Date: Thu, 11 Mar 2010 10:23:18 +0530

Thanks a lot Ben. Just couple of comments inline...

Thanks Again,
Nagesh

On Wed, Mar 10, 2010 at 10:31 PM, Ben Campbell <[email-masked]> wrote:

> I interpreted that to mean that you use the TLS mechanisms defined in the
> base protocols. It isn't intended to require you to use relays if you
> weren't already using them--just to say that, if you use relays, you must
> follow the TLS rules for relays.
>

[Nagesh] Thanks for clarifying. I can safely assume that ACM procedures can
be used for MSRP over TLS. Correct ? (Sorry for asking this - the draft
seems to TCP-centric and hence I am asking this explicitly.) Probably some
of the text proposed in the following thread may be used:

http://www.ietf.org/mail-archive/web/simple/current/msg08691.html

>
> Perhaps it could be clarified with something like "...defined in [RFC4975],
> and if MSRP Relays are used, in [RFC4976]."
>

[Nagesh] May be, the MSRP related statement shall be moved to Section 4.5 in
the draft.