Subject: [Ecrit] draft-ietf-ecrit-phonebcp requirements on IM protocols in endpoints

From: Gunnar Hellström <[email-masked]>
Date: Thu, 11 Feb 2010 00:58:24 +0100

I found a potential small inconsistency in draft-ietf-ecrit-phonebcp

draft-ietf-ecrit-phonebcp-14  has a requirement in the media section 14,
saying:

" ED-78 Endpoints supporting Instant Messaging (IM) MUST support both

   [RFC3428] and [RFC4975]."

Is this to require too much from the endpoints? Currently the users'
endpoints seldom implement both IM protocols. Would an endpoint only
supporting SIP Message be forbidden to use it in an emergency situation
because it does not have MSRP support?  

I would expect this double requirement on the PSAPs, so that they can handle
IM of both kinds.

This is an endpoint requirement, so I would expect the "both" replaced by
"either"/"or".

Proposal:

"ED-78 Endpoints supporting Instant Messaging (IM) MUST support either

   [RFC3428] or [RFC4975]."

I suggest to make that change in phonebcp unless there is a good explanation
why both IM protocols shall be required in the end-user devices.

Or is there a use case thought behind it:  Alice sends a SIP Message to the
PSAP saying "Help!". The PSAP want to establish an IM session to find out
all details and therefore tries to connect for an MSRP IM session.  If they
responded by SIP Message outside a dialogue, their messages would appear on
all terminals logged in on the same SIP address as the one that Alice uses
causing an integrity risk.

Was that the thought behind this double protocol requirement?

/Gunnar

---

From: "Bernard Aboba" <[email-masked]>
Date: Wed, 10 Feb 2010 19:49:08 -0800

+1

From: [email-masked] [mailto:[email-masked]] On Behalf Of
Gunnar Hellström
Sent: Wednesday, February 10, 2010 3:58 PM
To: Ecrit@Ietf. Org
Subject: [Ecrit] draft-ietf-ecrit-phonebcp requirements on IM protocols in
endpoints

Proposal:

   [RFC3428] or [RFC4975]."

/Gunnar