Re: [Anima-bootstrap] developments on 6tisch join scheduling
Brian E Carpenter <brian.e.carpenter@gmail.com> Wed, 17 August 2016 01:45 UTC
Return-Path: <brian.e.carpenter@gmail.com>
X-Original-To: anima-bootstrap@ietfa.amsl.com
Delivered-To: anima-bootstrap@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 5FAB112B064; Tue, 16 Aug 2016 18:45:56 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.7
X-Spam-Level:
X-Spam-Status: No, score=-2.7 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6U_3wyyj_vKv; Tue, 16 Aug 2016 18:45:54 -0700 (PDT)
Received: from mail-pf0-x244.google.com (mail-pf0-x244.google.com [IPv6:2607:f8b0:400e:c00::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id C934212B042; Tue, 16 Aug 2016 18:45:54 -0700 (PDT)
Received: by mail-pf0-x244.google.com with SMTP id y134so6434837pfg.3; Tue, 16 Aug 2016 18:45:54 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:to:references:cc:from:organization:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=9/dtC8VGTVbAt/2+E5LRjS0UjNRkTo6BDM+om1lRYnA=; b=vavtsA+09OY35tf5OGfptfAV+5JPn2VCAqQJ0w4DV5fUirc+Jz/DrKaVzEs4hSNVwD oO8pnwWmGw0LjtQqWWu/dCtcoqOdRNjzhBlHyE6p5ZpxhyZV5ELxZ1qi59T41K4+CBRn CREyuU2SxKzUvJZzZFQcxBk7ajAF8CLMoPcZo6GFYCg/WsHrDdBvX59t3+j/TvOiizLf ZZWDFDbhoHgojW2d8dbdQpE27cCiV20fH+ke+XkM9nMMJpwozjmn/xyBincGlCcoGdED Er7tNHMelzFFmPsWCQuwotfzJ/GOzpUxGS/6pTtUOXwrXDcfNIGX8YS7ySFK9EsmpeJL 9bQw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:cc:from:organization :message-id:date:user-agent:mime-version:in-reply-to :content-transfer-encoding; bh=9/dtC8VGTVbAt/2+E5LRjS0UjNRkTo6BDM+om1lRYnA=; b=RSmAmdWOOPd17Ki22BERexSmf3uGfST3AiBWoPX5+IwoFfUMphspO5Zux6K27nStoq SoNPUrbPMlV+yH1Ju5CbRupY2whOtw8Rvpb2fZzAwe9HzYPMpRMfEdj6zysEokkaW/uK ELlTo2vF3lBKKd8b2I8/jd9VgCr9jqynZ/kRnQ/brgD/u5K/WtEDaODrE9/UoScfrAqY dv4TaWvKNW9gSTf45/dKwIoKrvhe4VjIn99tmiBWn+ZA4X9w4lXQ5lUJ1fpafqFWyfAe JoYn/1TmydHsn+yYAPSZvWc/dWkSAi/RgN9Qdutc2/4c3i/RJSxdcDiReesSuz69Zw7Q xhiQ==
X-Gm-Message-State: AEkoouuCt4C/bZ5DBLTekS8eyvCkkvwaP6s2uj16ZbLwgIvLfyHYZoJdZsfTVOT61KsIeA==
X-Received: by 10.98.222.70 with SMTP id h67mr69573320pfg.128.1471398354174; Tue, 16 Aug 2016 18:45:54 -0700 (PDT)
Received: from ?IPv6:2406:e007:63aa:1:28cc:dc4c:9703:6781? ([2406:e007:63aa:1:28cc:dc4c:9703:6781]) by smtp.gmail.com with ESMTPSA id 6sm42370026pab.11.2016.08.16.18.45.51 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 16 Aug 2016 18:45:53 -0700 (PDT)
To: Michael Richardson <mcr+ietf@sandelman.ca>, tisch-security <6tisch-security@ietf.org>
References: <24944.1471387601@obiwan.sandelman.ca>
From: Brian E Carpenter <brian.e.carpenter@gmail.com>
Organization: University of Auckland
Message-ID: <36a58fbd-22a5-7dbe-6287-5bfca0d284fd@gmail.com>
Date: Wed, 17 Aug 2016 13:45:56 +1200
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0
MIME-Version: 1.0
In-Reply-To: <24944.1471387601@obiwan.sandelman.ca>
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/anima-bootstrap/Eihsop54odOFy005Bk6akhEMP6o>
Cc: anima-bootstrap@ietf.org
Subject: Re: [Anima-bootstrap] developments on 6tisch join scheduling
X-BeenThere: anima-bootstrap@ietf.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: Mailing list for the bootstrap design team of the ANIMA WG <anima-bootstrap.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/anima-bootstrap>, <mailto:anima-bootstrap-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/anima-bootstrap/>
List-Post: <mailto:anima-bootstrap@ietf.org>
List-Help: <mailto:anima-bootstrap-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/anima-bootstrap>, <mailto:anima-bootstrap-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 17 Aug 2016 01:45:56 -0000
> So the idea is to use the ANIMA GRASP discovery mechanism to find a proxy, > but in addition, in the reply, to get some kind of number If you are asking for *content* in a Discovery Response, you are actually asking for GRASP rapid mode (an objective included in the response message). I'm not suggesting that this is a problem. Regards Brian On 17/08/2016 10:46, Michael Richardson wrote: > > During discussions at IETF96, it became clear that the join ordering/time > sequence envisioned for 6tisch would be less possible than I thought. > The bad news is that a new mechanism might be hard to actually design. > The good news is that I think a new mechanism would put 6tisch join > and ANIMA bootstrap almost identical. > > To go back, the proposal was: > 1) a new pledge would send a NA with an EARO, which would turn into a > DAC/DAR process up to the 6LBR. The 6LBR would let the JCE know > about the new node through mechanism TBD. > The new pledge would receive a NA in reply, which, for the pledge > would acknowledge that they might be knocking on the right door. > (A network which didn't like that node would reply in some negative > fashion, which naturally could also be forged) > > 2) the JCE would reach out (via the proxy) to the pledge, on a schedule > determined by the JCE. The JCE would control the order of joining, > and since CoAP would be used with using something like: > draft-wang-6tisch-6top-protocol-00 > all joining nodes would remain quiet except when responding to > queries from the JCE. > > The goal of having the pledge be passive was one of bandwidth conservation, > the JCE would enroll only as many pledges as it felt it had available > bandwidth in the upper parts of the MESH DODAG tree. A 6tisch network might > allocate a rather small amount of bandwidth for join messages, and utilizing > the bandwidth responsabily is important. That means never wasting any energy > among the lower parts of the DODAG when the packets would just get dropped > further upwards. > > In discussions, it appears that the EARO as described in > draft-thubert-6lo-rfc6775-update-00 might be replaced by the Crypto-ID > of draft-sarikaya-6lo-ap-nd-02, and the process is slightly different. > > One additional reason why the passive pledge turns out to be a problem is > that the JCE does not actually know the wake/sleep schedule for the pledge. > In the 6tisch case, it ought to be possible for the pledge to sync up to > the schedule and so the proxy will know when it can transmit to it, but > in order to keep the proxy from having to store a lot of data coming from the > JCE, the JCE also needs to know the schedule out at the edge. This does not > seem unsolveable, but it was an additional concern raised. > > Meanwhile, in ANIMA bootstrap, the initial contact is through a GRASP > discovery (or DNSSD) to find a proxy. The new pledge uses the proxy to > initiate an EST session using the proxy. The enrollment process in the ANIMA > case is driven by the pledge, on the assumption that the ANIMA ACP has > sufficient bandwidth for normal congestion control present in TCP and CoAP to > deal with a limits. > > What is needed is a way to adjust things so that the pledges will attempt to > join in a way that does not overwhelm the network, and more so, that the proxy > nodes can easily police that they are doing so. > > So the idea is to use the ANIMA GRASP discovery mechanism to find a proxy, > but in addition, in the reply, to get some kind of number to seed a backoff > algorithm that causes the pledge to attempt to initiate the join process > at times deterministic to the network. I'm not talking about an exponential > backoff. > > This is where the hard part is, how to come up with a simple to describe, and > simple to code algorithm which would fill up the available bandwidth, and be > easily subdividable. > > By subdividable, I mean, if we pass 5% of the join bandwidth to proxy A, at > rank 3, that it would be able to easily pass some percent of that bandwidth > to a new proxy at rank 4 in a way that does not mean reconfiguring the entire > mesh to delegate bandwidth. > > Removing the subdivable property, some simple pseudo-random number generator, > with the right seed would be the right idea. A good PRNG ought to span > the available time space evenly. I don't have a solution, but I'm trying to > write up the requirements more clearly. > > -- > Michael Richardson <mcr+IETF@sandelman.ca>, Sandelman Software Works > -= IPv6 IoT consulting =- > > > > > > _______________________________________________ > Anima-bootstrap mailing list > Anima-bootstrap@ietf.org > https://www.ietf.org/mailman/listinfo/anima-bootstrap >
- Re: [Anima-bootstrap] [6tisch-security] developme… Pascal Thubert (pthubert)
- Re: [Anima-bootstrap] developments on 6tisch join… Brian E Carpenter
- [Anima-bootstrap] developments on 6tisch join sch… Michael Richardson
- Re: [Anima-bootstrap] [6tisch-security] developme… Michael Richardson