Re: [sipcore] I-D Action: draft-ietf-sipcore-proxy-feature-reqs-00.txt

"Worley, Dale R (Dale)" <dworley@avaya.com> Thu, 07 July 2011 18:49 UTC

Return-Path: <dworley@avaya.com>
X-Original-To: sipcore@ietfa.amsl.com
Delivered-To: sipcore@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C1B661F0C97 for <sipcore@ietfa.amsl.com>; Thu, 7 Jul 2011 11:49:10 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -103.388
X-Spam-Level:
X-Spam-Status: No, score=-103.388 tagged_above=-999 required=5 tests=[AWL=-0.016, BAYES_00=-2.599, RCVD_IN_DNSWL_LOW=-1, SARE_SUB_OBFU_Q1=0.227, USER_IN_WHITELIST=-100]
Received: from mail.ietf.org ([64.170.98.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id KgOkqKWApCl8 for <sipcore@ietfa.amsl.com>; Thu, 7 Jul 2011 11:49:10 -0700 (PDT)
Received: from co300216-co-outbound.net.avaya.com (co300216-co-outbound.net.avaya.com [198.152.13.100]) by ietfa.amsl.com (Postfix) with ESMTP id 3895E1F0C55 for <sipcore@ietf.org>; Thu, 7 Jul 2011 11:49:10 -0700 (PDT)
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: AowGAD3/FU7GmAcF/2dsb2JhbABTpzZwB7AhApshhjgEl2GLQg
X-IronPort-AV: E=Sophos;i="4.65,494,1304308800"; d="scan'208";a="289391301"
Received: from unknown (HELO co300216-co-erhwest.avaya.com) ([198.152.7.5]) by co300216-co-outbound.net.avaya.com with ESMTP; 07 Jul 2011 14:49:09 -0400
Received: from dc-us1hcex1.us1.avaya.com (HELO DC-US1HCEX1.global.avaya.com) ([135.11.52.20]) by co300216-co-erhwest-out.avaya.com with ESMTP; 07 Jul 2011 14:47:52 -0400
Received: from DC-US1MBEX4.global.avaya.com ([169.254.2.172]) by DC-US1HCEX1.global.avaya.com ([2002:870b:3414::870b:3414]) with mapi; Thu, 7 Jul 2011 14:49:08 -0400
From: "Worley, Dale R (Dale)" <dworley@avaya.com>
To: "sipcore@ietf.org" <sipcore@ietf.org>
Date: Thu, 07 Jul 2011 14:49:08 -0400
Thread-Topic: [sipcore] I-D Action: draft-ietf-sipcore-proxy-feature-reqs-00.txt
Thread-Index: Acw8xtXNBa4qiH7aTROq7p6uxNaD7AADja+Z
Message-ID: <CD5674C3CD99574EBA7432465FC13C1B222B1F574B@DC-US1MBEX4.global.avaya.com>
References: <20110707165628.18445.51358.idtracker@ietfa.amsl.com>
In-Reply-To: <20110707165628.18445.51358.idtracker@ietfa.amsl.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
acceptlanguage: en-US
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Subject: Re: [sipcore] I-D Action: draft-ietf-sipcore-proxy-feature-reqs-00.txt
X-BeenThere: sipcore@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: SIP Core Working Group <sipcore.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/sipcore>, <mailto:sipcore-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/sipcore>
List-Post: <mailto:sipcore@ietf.org>
List-Help: <mailto:sipcore-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/sipcore>, <mailto:sipcore-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 07 Jul 2011 18:49:10 -0000

I see in this draft:

   REQ-4: A SIP proxy MUST NOT, when indicating support of a feature/
   capability, make any assumptions that SIP entities in the signalling
   path that receive the indicator will support, or understand the
   meaning of, the feature/capability.

I think the phrasing of this can be improved.  More importantly, it doesn't
state that the proxy (that is doing the indicating) can do so even if intermediate
elements don't support the proxy-feature mechanism at all.  This might be a
more comprehensive way to express it:

   REQ-4: A SIP proxy MUST be able to indicate support of a
   feature/capability to all other SIP entities in the signaling path
   (that support this mechanism), even if some SIP entities in the
   signaling path (possibly including the UAC and/or UAS) do not
   support, or understand the meaning of, the feature/capability, or
   even this mechanism as a whole.

Dale