Re: [6tisch] 6P and Sf0 issue: Examples of error handling

Tengfei Chang <tengfei.chang@gmail.com> Fri, 04 March 2016 09:00 UTC

Return-Path: <tengfei.chang@gmail.com>
X-Original-To: 6tisch@ietfa.amsl.com
Delivered-To: 6tisch@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id B65071B3544 for <6tisch@ietfa.amsl.com>; Fri, 4 Mar 2016 01:00:03 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.999
X-Spam-Level:
X-Spam-Status: No, score=-1.999 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, HTML_MESSAGE=0.001, SPF_PASS=-0.001] autolearn=ham
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 wdkivBL1jJ4T for <6tisch@ietfa.amsl.com>; Fri, 4 Mar 2016 01:00:01 -0800 (PST)
Received: from mail-yw0-x22b.google.com (mail-yw0-x22b.google.com [IPv6:2607:f8b0:4002:c05::22b]) (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 EA7211B3543 for <6tisch@ietf.org>; Fri, 4 Mar 2016 01:00:00 -0800 (PST)
Received: by mail-yw0-x22b.google.com with SMTP id h129so39703988ywb.1 for <6tisch@ietf.org>; Fri, 04 Mar 2016 01:00:00 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc; bh=MFXVJnp1lzCDJvauvP7f/+V0qQY9J+DcYOg9WUYvvVU=; b=Nl+n564WkHrjryyLFecj6g/Ev3bajoBxwX9qarlaaRHFMg4jk2+UmGxyRhMbVo5S/m IgRjdUoN/aUX8yYuvwuNclPjkvzzCgko5R5qNDgPGQqeynPYI1O2lesqAQ5w7puPigjU 4T3fzFVaqgr1Um2Ji5NIG8uP+1Cic2hShI2iGiIU0tIm0V01CkDGbzbP6Zr947m1ot67 P86AxDKNzpE7SQSB4AAa4XwJe4W+q3b2qstel3YmrWYkFkFqfSbkoxK7QTeViFv5Z+kq 9/VmovYiFs2EwR2thjUgVKOi0vDyvKR7kGTUatP3wGVmN6WOVrikeeLNii/vx/wHX3xw tLew==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc; bh=MFXVJnp1lzCDJvauvP7f/+V0qQY9J+DcYOg9WUYvvVU=; b=kXrqALN5jhvrb3KyCNukXCCoufsBu1TN38IGP2/sIujlzTma3R10gsoMAqN819rKww HlCZnIOTtsO9Kpuu41Gu49aZGPQd2Flr8WRTfx1WwCRbyx99zm3N5w7RFME1lHTQET24 1uR1r4jbHtepxTT4NVhMUva8cCMZi/jf6YgQmv12EfS2AyLg+fTlzYo3qZFz+vUGJAAI SiTStrjPmDzcs7nGdxjmIMk2ofah/PRkzZsUV/P+i0yz62KriyWLrnQM7eQZOIq+ay/V c298Gu4K6SPJcGC3vA2iA1cu2z8NCclheW8xhMgLpeiWnkEK3XRlC/vgjYOAvwu1aC1F nwVQ==
X-Gm-Message-State: AD7BkJKLcw0ARAH2cPAl2OIQfOLTHQmIlxFyyaMU1LBEGiGA9I7Fpr05HIGit008Ap9x6zGBqt93A1JjXQ7JxQ==
MIME-Version: 1.0
X-Received: by 10.129.145.82 with SMTP id i79mr4052037ywg.345.1457082000222; Fri, 04 Mar 2016 01:00:00 -0800 (PST)
Received: by 10.37.116.151 with HTTP; Fri, 4 Mar 2016 01:00:00 -0800 (PST)
In-Reply-To: <CAH7SZV_o4rObdYF0ocBHHaHK=Lma_aDxb7xZcVoyyuLcTykPKw@mail.gmail.com>
References: <CAH7SZV_o4rObdYF0ocBHHaHK=Lma_aDxb7xZcVoyyuLcTykPKw@mail.gmail.com>
Date: Fri, 4 Mar 2016 10:00:00 +0100
Message-ID: <CAAdgstQKhJOQGGRfLq6RgW-yTVW4PxpCRtvop0F30PXHhFMccg@mail.gmail.com>
From: Tengfei Chang <tengfei.chang@gmail.com>
To: "Prof. Diego Dujovne" <diego.dujovne@mail.udp.cl>
Content-Type: multipart/alternative; boundary=94eb2c093a3e082e57052d3557c6
Archived-At: <http://mailarchive.ietf.org/arch/msg/6tisch/ZNFeiaa9SleVtLqptGcvfIaMgpg>
Cc: "6tisch@ietf.org" <6tisch@ietf.org>
Subject: Re: [6tisch] 6P and Sf0 issue: Examples of error handling
X-BeenThere: 6tisch@ietf.org
X-Mailman-Version: 2.1.15
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" <6tisch.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/6tisch>, <mailto:6tisch-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/6tisch/>
List-Post: <mailto:6tisch@ietf.org>
List-Help: <mailto:6tisch-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/6tisch>, <mailto:6tisch-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 04 Mar 2016 09:00:03 -0000

Hello Diego,

*For IANA_6TOP_CMD_ROLLBACK command: *

I think I understand what you are trying to solve. But using
IANA_6TOP_CMD_ROLLBACK
has another issue: how to decide when to send the command. I think this is
the same question for setting the value of 6P_TIMEOUT.
Also if a transaction timeout because of bad link quality or lost
connection, sending another packet is not a good idea.

*For Retry handling:*

First, I think whether retry or not is a decision made by scheduling
function. For 6P, it just forwards this message to upper layer (such as SF0)

If retries are required, I think it makes sense that retrying within a
transaction.

What do you think?

Tengfei

On Thu, Mar 3, 2016 at 9:41 PM, Prof. Diego Dujovne <
diego.dujovne@mail.udp.cl> wrote:

> Dear all,
>            One of the sections I would like to add to
> the SF0 draft is the examples of error handling.
>
> One example could be Timeout handling:
> When a transaction times out, either a packet is lost,
> the destination node lost connectivity or it is too busy
> to answer on time.
> Consequence: The transaction, in any stage, should
> be rolled back by both ends.
> Here, both nodes are expected to Timeout.
> Section 3.6.2 of the sublayer draft "Aborting a
> 6P transaction", cannot be used, since in this case
> there is no response.
> I propose to issue a rollback command such as
> "IANA_6TOP_CMD_ROLLBACK" to the destination
> node using the same token from the original transaction,
> and do not wait for an answer.
> This enables the source node to try a new transaction
> before the destination node times out, thus reducing
> delay.
>
> Would you agree in adding this command to reduce
> delay?
>
> Another issue should be Retry handling, in case of
> timeout.
> Do we allow retries within a transaction?
> If we allow retries, the maximum number of retries before
> considering a transaction failed should be configured on
> the SF.
>
> Thank you.
> Regards,
>
>                                     Diego Dujovne
>
>
> --
> DIEGO DUJOVNE
> Académico Escuela de Ingeniería en Informática y Telecomunicaciones
> Facultad de Ingeniería UDP
> www.ingenieria.udp.cl
> (56 2) 676 8125
>
> _______________________________________________
> 6tisch mailing list
> 6tisch@ietf.org
> https://www.ietf.org/mailman/listinfo/6tisch
>
>