IETF Logo Mail Archive

Re: [Roll] 'S' field in MPL Options

"Jonathan Hui (johui)" <johui@cisco.com> Thu, 22 November 2012 01:06 UTC

Return-Path: <johui@cisco.com>
X-Original-To: roll@ietfa.amsl.com
Delivered-To: roll@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 2ED3921E8044 for <roll@ietfa.amsl.com>; Wed, 21 Nov 2012 17:06:18 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -10.598
X-Spam-Level:
X-Spam-Status: No, score=-10.598 tagged_above=-999 required=5 tests=[AWL=-0.000, BAYES_00=-2.599, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_HI=-8]
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 Kgm6gA9McJL7 for <roll@ietfa.amsl.com>; Wed, 21 Nov 2012 17:06:17 -0800 (PST)
Received: from rcdn-iport-6.cisco.com (rcdn-iport-6.cisco.com [173.37.86.77]) by ietfa.amsl.com (Postfix) with ESMTP id 7C5EA21E8034 for <roll@ietf.org>; Wed, 21 Nov 2012 17:06:17 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=4308; q=dns/txt; s=iport; t=1353546377; x=1354755977; h=from:to:cc:subject:date:message-id:references: in-reply-to:mime-version; bh=2NxmFh6RWfJH7DtvG2HI4iEFXXh80pzemEO0s2PZ6dE=; b=djzrqTrv8Wu14cRwqYGYQ52Wo5GbSahRzliWUoFYZ5PBxMamA3EZ+k/N 4HNezthrsBm0BLfvnjNXzn3mNtSSWPL33IHJ+D7wKw+cVt7n8QpZENbRP PPGyJDkigFTBdq2AB8kPpR7XyREysw81GRWRKn5ruQ5d7YwaYt+WM11r/ s=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: Av8EADV5rVCtJV2d/2dsb2JhbABEwhgWc4IfAQEEAQEBawsQAgEIBAoUHQcnCxQRAgQOBQiIBQu/N4w0hAJhA4gnjnOPJYJvghk
X-IronPort-AV: E=McAfee;i="5400,1158,6903"; a="145034668"
Received: from rcdn-core-6.cisco.com ([173.37.93.157]) by rcdn-iport-6.cisco.com with ESMTP; 22 Nov 2012 01:06:17 +0000
Received: from xhc-rcd-x06.cisco.com (xhc-rcd-x06.cisco.com [173.37.183.80]) by rcdn-core-6.cisco.com (8.14.5/8.14.5) with ESMTP id qAM16G2o007460 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL); Thu, 22 Nov 2012 01:06:16 GMT
Received: from xmb-rcd-x04.cisco.com ([169.254.8.108]) by xhc-rcd-x06.cisco.com ([173.37.183.80]) with mapi id 14.02.0318.001; Wed, 21 Nov 2012 19:06:16 -0600
From: "Jonathan Hui (johui)" <johui@cisco.com>
To: Dario Tedeschi <dat@exegin.com>
Thread-Topic: [Roll] 'S' field in MPL Options
Thread-Index: AQHNyE2SRfkeZRROFE+IAT0ZGkHBPQ==
Date: Thu, 22 Nov 2012 01:06:15 +0000
Message-ID: <B50D0F163D52B74DA572DD345D5044AF0F779FCF@xmb-rcd-x04.cisco.com>
References: <50AD18CC.90907@gridmerge.com> <50AD7947.8050303@exegin.com>
In-Reply-To: <50AD7947.8050303@exegin.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [10.21.74.19]
Content-Type: multipart/alternative; boundary="_000_B50D0F163D52B74DA572DD345D5044AF0F779FCFxmbrcdx04ciscoc_"
MIME-Version: 1.0
Cc: Roll WG <roll@ietf.org>
Subject: Re: [Roll] 'S' field in MPL Options
X-BeenThere: roll@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Routing Over Low power and Lossy networks <roll.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/roll>, <mailto:roll-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/roll>
List-Post: <mailto:roll@ietf.org>
List-Help: <mailto:roll-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/roll>, <mailto:roll-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 22 Nov 2012 01:06:18 -0000

The question is whether we want to allow sub-TLVs in the MPL Option.  A future specification could introduce sub-TLVs, but that would not be backwards compatible if we did not have an explicit length for the seed-id.  Given the small namespace for IPv6 Options, we might want to consider having a way of including additional fields that is backwards compatible.

--
Jonathan Hui

On Nov 21, 2012, at 5:00 PM, Dario Tedeschi <dat@exegin.com<mailto:dat@exegin.com>> wrote:

I agree

The 'S' field seems redundant, because an implementation would still need to read the Length field so it can make sure the 'S' field wasn't lying.

- Dario

On 21/11/2012 10:09 AM, Robert Cragie wrote:
Referring to http://tools.ietf.org/html/draft-ietf-roll-trickle-mcast-02 section 4.1 - maybe I'm missing something but why is the 'S' field needed? Given that the text for Opt Data Len is wrong (it should say "Length of the Option Data field in octets.  MUST be set to 2, 4, 10 or 18"), surely Opt Data Len is sufficient for working out which Seed IDs are in there?

Robert




_______________________________________________
Roll mailing list
Roll@ietf.org<mailto:Roll@ietf.org>
https://www.ietf.org/mailman/listinfo/roll


_______________________________________________
Roll mailing list
Roll@ietf.org<mailto:Roll@ietf.org>
https://www.ietf.org/mailman/listinfo/roll

v2.23.0 | Report a Bug | By Email