Re: [Roll] mixture of storing and non-storing nodes

Michael Richardson <mcr+ietf@sandelman.ca> Fri, 24 August 2012 19:23 UTC

Return-Path: <mcr@sandelman.ca>
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 B371421F84C5 for <roll@ietfa.amsl.com>; Fri, 24 Aug 2012 12:23:06 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.932
X-Spam-Level:
X-Spam-Status: No, score=-1.932 tagged_above=-999 required=5 tests=[AWL=0.022, BAYES_00=-2.599, HOST_MISMATCH_NET=0.311, IP_NOT_FRIENDLY=0.334]
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 vFOjsDCctCZv for <roll@ietfa.amsl.com>; Fri, 24 Aug 2012 12:23:06 -0700 (PDT)
Received: from relay.sandelman.ca (relay.cooperix.net [67.23.6.41]) by ietfa.amsl.com (Postfix) with ESMTP id E4BCA21F84A7 for <roll@ietf.org>; Fri, 24 Aug 2012 12:23:04 -0700 (PDT)
Received: from sandelman.ca (74-115-197-225.eng.wind.ca [74.115.197.225]) by relay.sandelman.ca (Postfix) with ESMTPS id 9E4038656 for <roll@ietf.org>; Fri, 24 Aug 2012 15:17:51 -0400 (EDT)
Received: from sandelman.ca (quigon.sandelman.ca [127.0.0.1]) by sandelman.ca (Postfix) with ESMTP id 56680CA0D2 for <roll@ietf.org>; Fri, 24 Aug 2012 14:32:33 -0400 (EDT)
From: Michael Richardson <mcr+ietf@sandelman.ca>
To: roll WG <roll@ietf.org>
In-reply-to: <B7828579-4864-4CBA-A999-808F394D543F@cisco.com>
References: <CAErDfUQV2E5H66k9YjRSGF8RmA=xhQzrDwpyTRBJ8WQUZh3diw@mail.gmail.com> <B7828579-4864-4CBA-A999-808F394D543F@cisco.com>
Comments: In-reply-to "JP Vasseur (jvasseur)" <jvasseur@cisco.com> message dated "Wed, 22 Aug 2012 06:15:05 -0000."
X-Mailer: MH-E 8.3; nmh 1.3; XEmacs 21.4 (patch 22)
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="=-=-="; micalg="pgp-sha1"; protocol="application/pgp-signature"
Date: Fri, 24 Aug 2012 14:32:33 -0400
Message-ID: <30393.1345833153@sandelman.ca>
Sender: mcr@sandelman.ca
Subject: Re: [Roll] mixture of storing and non-storing nodes
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: Fri, 24 Aug 2012 19:23:08 -0000

    OG> John Ko posted a draft a few days ago about how we might accommodate a
    OG> mixture of storing and non-storing nodes in a network more efficiently
    OG> than making one of them leaf nodes. Searching through the ROLL mail
    OG> archives, it was clear at the time that there was no use case for
    OG> having a network that has a mixture of storing and non-storing
    OG> nodes.

    JP> I cannot agree more - actually we even have a partial to the
    JP> problem during the initial design phase and the WG collectively
    JP> decided not to mix storing and non-storing in light of the added
    JP> complexity. I would also appreciate the feedback of the WG on
    JP> this, and not add complexity unless this becomes a strong
    JP> requirement. 

I believe that use cases for storing and non-storing nodes would appear
as optimizations (particularly in the p2p heavy LLNs) if we could figure
out how to make it work.

I think that the major problem was that nodes below the root needed to
know if there downstreams nodes were storing or not, and thus
non-storing nodes wound up picking up significant resource impact, when
those nodes were supposed to be lighter weight.

-- 
Michael Richardson
-at the cottage-