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

Dario Tedeschi <dat@exegin.com> Thu, 22 November 2012 21:27 UTC

Return-Path: <dat@exegin.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 9DE2D21F86C3 for <roll@ietfa.amsl.com>; Thu, 22 Nov 2012 13:27:43 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -3.392
X-Spam-Level:
X-Spam-Status: No, score=-3.392 tagged_above=-999 required=5 tests=[AWL=0.206, BAYES_00=-2.599, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-1]
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 7OsnwJh7G3Js for <roll@ietfa.amsl.com>; Thu, 22 Nov 2012 13:27:41 -0800 (PST)
Received: from mail-pb0-f44.google.com (mail-pb0-f44.google.com [209.85.160.44]) by ietfa.amsl.com (Postfix) with ESMTP id 0C43B21F8683 for <roll@ietf.org>; Thu, 22 Nov 2012 13:27:40 -0800 (PST)
Received: by mail-pb0-f44.google.com with SMTP id uo1so6040563pbc.31 for <roll@ietf.org>; Thu, 22 Nov 2012 13:27:40 -0800 (PST)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:x-gm-message-state; bh=RR6R+JZ7d911nNUha0BAgTIbG6wGdTyPzNbfX6fgfZc=; b=BlirvZ4rcFAW2N09tUZgx8KMRd46teQu+Kxiw+ImpBqIiTLm7bNTxsvVPU9MSdx7+N xYaLqfg9n+3EFwjn8Jth+8xY9kKAzb0mR9Hy5JhOACTHmhlRNgOxAmpwO/gKqv4fTbOU qqyXwm8OXEiOljgQE7hhjpit8kCa0XbK2j9kCHKf4cwWR9kumaKW6ov0THS+pkdBf1/c 72NjASgius6XgnP1th9H7SBEk2M7iZCoQAGQGIKlVpb9YPFN6CcM9YPtnuvqYR41zJUa fiZwCgDh4usYIADK7PxFjIs+NjoTRVb+hYAtMIV1gEx7yt69MZ2njvJSk4UCVovxr891 1Yng==
Received: by 10.66.79.195 with SMTP id l3mr2096461pax.82.1353619660716; Thu, 22 Nov 2012 13:27:40 -0800 (PST)
Received: from [172.16.1.52] ([184.71.143.130]) by mx.google.com with ESMTPS id ok3sm2612599pbb.11.2012.11.22.13.27.38 (version=SSLv3 cipher=OTHER); Thu, 22 Nov 2012 13:27:39 -0800 (PST)
Message-ID: <50AE98BE.3000007@exegin.com>
Date: Thu, 22 Nov 2012 13:27:26 -0800
From: Dario Tedeschi <dat@exegin.com>
User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:7.0) Gecko/20110922 Thunderbird/7.0
MIME-Version: 1.0
To: "Jonathan Hui (johui)" <johui@cisco.com>
References: <50AD18CC.90907@gridmerge.com> <50AD7947.8050303@exegin.com> <B50D0F163D52B74DA572DD345D5044AF0F779FCF@xmb-rcd-x04.cisco.com>
In-Reply-To: <B50D0F163D52B74DA572DD345D5044AF0F779FCF@xmb-rcd-x04.cisco.com>
Content-Type: multipart/alternative; boundary="------------010805070803090301030208"
X-Gm-Message-State: ALoCoQmAG9Pr5kvQIhO01nMGYbQ5INvwjSXao91xPobh1Y1qNvaImUQBGe0Oz4YnGs1fQWgzLFuL
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 21:27:43 -0000

I have no strong opinion on the matter. Besides, I don't want to get 
stuck in an argument over 1 bit. :-)

If you think sub-TLVs could be a real use-case, I'm fine with it. 
However, I will say that I'm unaware of any hop-options that have sub-TLVs.

- Dario


On 21/11/2012 5:06 PM, Jonathan Hui (johui) wrote:
>
> 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
>>> https://www.ietf.org/mailman/listinfo/roll
>>
>> _______________________________________________
>> Roll mailing list
>> Roll@ietf.org <mailto:Roll@ietf.org>
>> https://www.ietf.org/mailman/listinfo/roll
>