Re: [6tsch] Is generic management method possible?
Thomas Watteyne <watteyne@eecs.berkeley.edu> Tue, 10 September 2013 17:17 UTC
Return-Path: <twatteyne@gmail.com>
X-Original-To: 6tsch@ietfa.amsl.com
Delivered-To: 6tsch@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id B23D021F9951 for <6tsch@ietfa.amsl.com>; Tue, 10 Sep 2013 10:17:24 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.448
X-Spam-Level:
X-Spam-Status: No, score=-0.448 tagged_above=-999 required=5 tests=[AWL=0.929, BAYES_00=-2.599, FM_FORGED_GMAIL=0.622, HTML_MESSAGE=0.001, J_CHICKENPOX_41=0.6, NO_RELAYS=-0.001]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id dUmpH7r7V1m5 for <6tsch@ietfa.amsl.com>; Tue, 10 Sep 2013 10:17:23 -0700 (PDT)
Received: from mail-pa0-x235.google.com (mail-pa0-x235.google.com [IPv6:2607:f8b0:400e:c03::235]) by ietfa.amsl.com (Postfix) with ESMTP id 945D921F994A for <6tsch@ietf.org>; Tue, 10 Sep 2013 10:17:22 -0700 (PDT)
Received: by mail-pa0-f53.google.com with SMTP id lb1so7953340pab.40 for <6tsch@ietf.org>; Tue, 10 Sep 2013 10:17:22 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:content-type; bh=Q+Y1+jEcgLyEz4xDwVdQk+XvK1Lh/uw50ql3T7iF2+Y=; b=JHqeCTlSJ46UGN1O9A6UrDxEPgod+N2X7E4Cm6SN/BcNZovJyniD2ORrE+1y8WLjzJ N92sgPbImTB+ee38YRrWSq5u6FuesqWUDJnqYpOCih7IpqozC4b6tyNQdo+M+CrvFqEI 7ADzzpCoiT04tkkxDtVD0KQW58NH+KkOgyFoVQcO71SAN29E2vaYDnGmBtE11prJnums m8eaOBA/KB9Thk4QCPMkqZzM5IKZkZh9Cw/eCCjxvQB2iRfdrWQRtRA3set7jjG5Ptv/ HVYkf3vXIpx4Rc4QgK4YgnmkcgofKq68JzEP47Ax3kx9hg5yhjhqh3WaDL/YiUkcyUI5 mQow==
X-Received: by 10.66.248.161 with SMTP id yn1mr28128237pac.0.1378833442255; Tue, 10 Sep 2013 10:17:22 -0700 (PDT)
MIME-Version: 1.0
Sender: twatteyne@gmail.com
Received: by 10.66.147.193 with HTTP; Tue, 10 Sep 2013 10:17:01 -0700 (PDT)
In-Reply-To: <CAAzoce4Lio-6g1-0-hM44z1St6bgwvc15tWiY4+-06Hn3560pg@mail.gmail.com>
References: <CAAzoce6CvKLUxr2SDD0pp4NGRGhd8n2+XXzCep6EDjUF3+d67Q@mail.gmail.com> <CADJ9OA8Ectu1Phk7XkVsm0oa50ry084gPF7Hb7DUUZ=Nv=rLnA@mail.gmail.com> <F085911F642A6847987ADA23E611780D1859AB93@hoshi.uni.lux> <CAAzoce4Lio-6g1-0-hM44z1St6bgwvc15tWiY4+-06Hn3560pg@mail.gmail.com>
From: Thomas Watteyne <watteyne@eecs.berkeley.edu>
Date: Tue, 10 Sep 2013 10:17:01 -0700
X-Google-Sender-Auth: CB6NnHMEsusWfjfSHLc262-SiDo
Message-ID: <CADJ9OA9zO1jiP1d7swxOa4jQjrA1iwU+4dZK2wG4M1OJbZqetA@mail.gmail.com>
To: "6tsch@ietf.org" <6tsch@ietf.org>
Content-Type: multipart/alternative; boundary="047d7b15b04387b90204e60aad55"
Subject: Re: [6tsch] Is generic management method possible?
X-BeenThere: 6tsch@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: "Discuss link layer model for Deterministic IPv6 over the TSCH mode of IEEE 802.15.4e, and impacts on RPL and 6LoWPAN such as resource allocation" <6tsch.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/6tsch>, <mailto:6tsch-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/6tsch>
List-Post: <mailto:6tsch@ietf.org>
List-Help: <mailto:6tsch-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/6tsch>, <mailto:6tsch-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 10 Sep 2013 17:17:24 -0000
Qin, I think we all largely agree. What follows is some context to make entirely sure we're talking about the same thing. It's written in -vv mode, so please be patient. The following illustrates the different interactions. +-----+ +--------------------+ +--------------------+ | PCE |<==*(3)*==>| 6top ME ^ | | | +-----+ +---------------|----+ +--------------------+ | CoAP | | | CoAP | +-------------- | ---+ +--------------------+ | . *(1)* | | . | | . | | | . | +-------------- | ---+ +--------------------+ | 6top V |<==*(2)*==>| 6top | +--------------------+ +--------------------+ | IEEE802.15.4e TSCH | | IEEE802.15.4e TSCH | +--------------------+ +--------------------+ 6top is a sublayer which lives above MAC. It is described in http://tools.ietf.org/html/draft-wang-6tsch-6top-00 and defines *(1)* the hooks for an upper layer to interact with the TSCH schedule and *(2)* a negotiation mechanism between two nodes to manage soft cells allocation. * (1)* is used by the 6top management entity (6top ME). *(2)* is used by neighbor nodes to manage soft cells. In a centralized case, the PCE talks to the 6top ME over some application-level protocol *(3)*. While this is still in debate, CoAP looks like an interesting choice (Raghu and Xavi will be leading a discussion about CoAP during this Friday's call). About the different interactions depicted above: - The discussion about the flows we had last week deals with *(3)*. We identified 5 flows, and started discussing the contents of the report flows, as captured in https://bitbucket.org/6tsch/meetings/wiki/report_flow_contents. - The interaction marked *(1)* is inside the mote. Since it does not involve sending bytes over the air, I would argue that it is implementation-specific, and out of scope of what we want to standardize. And while http://tools.ietf.org/html/draft-wang-6tsch-6top-00#section-2.4 defines a set of commands, an implementation will be compliant as long as it trigger the correct "over-the-air" behavior. - Since we are working on the centralized case first, and that it makes most sense to use hard cells in the centralized case, *(2)* hasn't received much attention lately. I believe that we should keep what's defined in http://tools.ietf.org/html/draft-wang-6tsch-6top-00 and resume working on it when we tackle the distributed case. Coming back to our discussion about formats, I expect a packet of interaction to look *(3)* something like: +------...-------+------+---------+ | several header | CoAP | *payload* | +------...-------+------+---------+ CoAP will give us "services" such as resource and URIs, method (GET/POST/PUT/DELETE) and optional confirmable messages. Using those simply means that the 6top ME will not have to re-define those "services", hence that the format of the *payload* gets simpler. CoAP is also "application-agnostic", i.e. it just transports the *payload* between two end-points, without knowing anything about what that *payload* contains. The distributed case is a different problem. We are talking about using protocols such as RSVP/NSIS, which are more than just "transporting" data, since they come with precise interaction models. Given this, I would argue that we will not be able to reuse the exact same *payload* format. That being said, it we opt for flexible encoding of generic information such as "a request for bandwidth", or "a statistic about cell usage", we might be able to reuse those as building blocks whenever needed by RSVP/NSIS (or a simpler version thereof). I believe in the JSON/BSON/CBOR path we are following, and that it will give us the re-usability we are looking for. Is this in line with what you're thinking? Thomas On Tue, Sep 10, 2013 at 5:48 AM, Qin Wang <qinwang@berkeley.edu> wrote: > Hi Thomas and Maria Rita, > > I totally agree with you that we should focus on centralized approach in > the current step. But I cannot see it is very difficult to cover > distributed case. Maybe I miss something. > > To be clear, in my mind, the exchanged messages in distributed case is > that between 6top and some Reservation protocol like RSVP/NSIS in upper > layer. In another word, it is about exchanging messages inside a node, > instead of exchanging messages among neighbors. I don't understand why for > different upper layer Reservation protocol, the control flows from/to 6top > could be different significantly. Can you explain a little more? > > Thanks > Qin > > > > > > > On Tue, Sep 10, 2013 at 2:45 PM, Maria Rita PALATTELLA < > maria-rita.palattella@uni.lu> wrote: > >> Qin, I agree too about defining the formats in a way that we can reuse >> them for the distributed case. But, for the time being, I would be focused >> on the centralized approach and try to find a solution for it. And then, >> move to the distributed one (that for sure will raise other issues up).** >> ** >> >> Let’s try to solve the problems one by one! **** >> >> Maria Rita **** >> >> ** ** >> >> *From:* 6tsch-bounces@ietf.org [mailto:6tsch-bounces@ietf.org] *On >> Behalf Of *Thomas Watteyne >> *Sent:* Tuesday, September 10, 2013 6:24 AM >> *To:* 6tsch@ietf.org >> *Subject:* Re: [6tsch] Is generic management method possible?**** >> >> ** ** >> >> Qin,**** >> >> ** ** >> >> I fully agree that being able to reuse some formats in the distributed >> case is important. The question about the exact protocol to use for >> negotiation between neighbors in the distributed case is a very broad one. >> It is too early to discuss that. We can, however, keep the distributed case >> in mind when proposing formats.**** >> >> ** ** >> >> Thomas**** >> >> ** ** >> >> On Mon, Sep 9, 2013 at 1:57 PM, Qin Wang <qinwang@berkeley.edu> wrote:*** >> * >> >> Hi All,**** >> >> ** ** >> >> In the previous discussion, we have figured out 5 control flows between >> PCE and node, which were expressed in the context of centralized case. >> Obviously, it will be great if the messages in those identified control >> flows are generic, suitable for both centralized and distributed case. >> During last Friday's call, it was mentioned but is still a open issue. I >> propose to continue the discussion in this thread.**** >> >> ** ** >> >> Comparing the role of PCE in centralized case,I think RSVP/NSIS will play >> similar role in distributed case. In another word, instead of exchanging >> message with PCE via a network, 6top Management Entity will exchange >> message with a Reservation Entity like RSVP/NSIS inside the same node. The >> question is if it is possible to use same design in the two cases. (I'm >> not expert on RSVP and NSIS, please input your opinions).**** >> >> ** ** >> >> Firstly, I think the contents of messages in the centralized and >> distributed case are overlap in a big portion. For example, both of them >> need to send action flow, both of them need statistics data, and so on.** >> ** >> >> ** ** >> >> Secondly, in terms of Message Exchange, the two cases are similar. The >> only difference is, in centralized case, the control messages are carried >> by CoAP as payload; and in distributed case, the control messages are >> "sent" via internal pointer. **** >> >> ** ** >> >> Make sense?**** >> >> ** ** >> >> Qin**** >> >> ** ** >> >> ** ** >> >> >> _______________________________________________ >> 6tsch mailing list >> 6tsch@ietf.org >> https://www.ietf.org/mailman/listinfo/6tsch**** >> >> ** ** >> >> _______________________________________________ >> 6tsch mailing list >> 6tsch@ietf.org >> https://www.ietf.org/mailman/listinfo/6tsch >> >> >
- [6tsch] Is generic management method possible? Qin Wang
- Re: [6tsch] Is generic management method possible? Thomas Watteyne
- Re: [6tsch] Is generic management method possible? Maria Rita PALATTELLA
- Re: [6tsch] Is generic management method possible? Qin Wang
- Re: [6tsch] Is generic management method possible? Thomas Watteyne
- Re: [6tsch] Is generic management method possible? Qin Wang