Re: [trill] Comments on draft-ietf-trill-cmt-00

Donald Eastlake <d3e3e3@gmail.com> Thu, 18 October 2012 03:41 UTC

Return-Path: <d3e3e3@gmail.com>
X-Original-To: trill@ietfa.amsl.com
Delivered-To: trill@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C061921F8522 for <trill@ietfa.amsl.com>; Wed, 17 Oct 2012 20:41:37 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -101.57
X-Spam-Level:
X-Spam-Status: No, score=-101.57 tagged_above=-999 required=5 tests=[AWL=-1.817, BAYES_00=-2.599, MIME_CHARSET_FARAWAY=2.45, RCVD_IN_DNSWL_LOW=-1, USER_IN_WHITELIST=-100, WEIRD_QUOTING=1.396]
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 UgEdM0upwzkH for <trill@ietfa.amsl.com>; Wed, 17 Oct 2012 20:41:37 -0700 (PDT)
Received: from mail-ie0-f172.google.com (mail-ie0-f172.google.com [209.85.223.172]) by ietfa.amsl.com (Postfix) with ESMTP id E678921F851E for <trill@ietf.org>; Wed, 17 Oct 2012 20:41:36 -0700 (PDT)
Received: by mail-ie0-f172.google.com with SMTP id 9so14889130iec.31 for <trill@ietf.org>; Wed, 17 Oct 2012 20:41:36 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; bh=gcWWRgMsfvzrVoub2mupO1Lr1wNFPyjqlzRpuNlWK7k=; b=FiE7ZqyThljHsz7v/gr6BGbuC0+ifXlGNjv/BI/2YrBib/rmkT8bqhIbUPGxoYr0U2 ADhWHcLXzMAxE9QVNnK8zbDL0uDn1j65Mj36kXwbItVMkUBmWI3YCvXJSMMvMH7MSV1D 4pMA2HkwSvfzkuwZGzyRJ9NVe3/OCULnqiJw6l72EXnUaVkUxuAexZbEkpsmJplRIsop rCs8fzUBa4nPldW6E8GX2YXbf69Tndu29ykJxwIm0qeetu3X9iBu9SMeL7m9GtBZBUNe F0TvyBygDEuPxyFPy5U2y6yWO/e3960v2EHk8iooOraa3RcqMZVpR1ZgGLoFudIr2fgy MUKg==
Received: by 10.50.219.229 with SMTP id pr5mr3611356igc.59.1350531695969; Wed, 17 Oct 2012 20:41:35 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.64.176.134 with HTTP; Wed, 17 Oct 2012 20:41:15 -0700 (PDT)
In-Reply-To: <OFFD6EA303.0B8F1B6B-ON48257A98.0011CB3D-48257A98.0013BF1E@zte.com.cn>
References: <CAF4+nEFrkrTnKOU72B7Bu+aRfdf7g2pQq6uUQoMADUfcO1DOxQ@mail.gmail.com> <OFFD6EA303.0B8F1B6B-ON48257A98.0011CB3D-48257A98.0013BF1E@zte.com.cn>
From: Donald Eastlake <d3e3e3@gmail.com>
Date: Wed, 17 Oct 2012 23:41:15 -0400
Message-ID: <CAF4+nEEujrCHGA807qBCF25w88Qe94z11Sdd1cwX2YDp+RuB3g@mail.gmail.com>
To: zhai.hongjun@zte.com.cn
Content-Type: text/plain; charset=GB2312
Content-Transfer-Encoding: quoted-printable
Cc: trill@ietf.org
Subject: Re: [trill] Comments on draft-ietf-trill-cmt-00
X-BeenThere: trill@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: "Developing a hybrid router/bridge." <trill.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/trill>, <mailto:trill-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/trill>
List-Post: <mailto:trill@ietf.org>
List-Help: <mailto:trill-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/trill>, <mailto:trill-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 18 Oct 2012 03:41:37 -0000

Hi,

On Sun, Oct 14, 2012 at 11:34 PM, <zhai.hongjun@zte.com.cn> wrote:
>
> Hi Donald,
>
> > - The draft should be clear that when doing the RPFC for a
> > multi-destination TRILL Data packet ingressed with a virtual RBridge
> > nickname, the RPFC must assume that the TRILL Data packet might use
> > any of the trees that any of the RBk might use.
>
> Do you mean that RBn ignores the egress nickname in a received
> multi-destinaion TRILL data packet with a virtual RBridge nickname
> when it does RPFC for that packet in that case? Or if I am wrong,
> please give a clearer explanation on that sentence by using an example.

One way to look at the RPFC is that at each RBridge port there is a
table of pairs of acceptable { ingress nickname, tree } where tree is
the egress nickname in a multi-destination TRILL Data packet. Say RB1
is not going to use all of the distribution trees being computed for a
campus. Then RB1 can optionally list the tress it is going to use.
This will reduce the amount of RPFC state at all the other RBridges in
the campus because instead of having an entry for some port for
ingress RB1 paired with every tree it only needs entries for ingress
RB1 paired with the trees RB1 says it might use.

Say a virtual RBridge RBv is in use as in the CMT draft. Then the edge
group RBridges, when converting a frame off the link to a TRILL Data
packet, will use RBv as the ingress nickname. Say you have 8 trees
being calculated for a campus and three edge group RBridges each using
two different trees. So the edge group RBridges all together only use
6 different trees. Then you need RPFC entries at every other RBridge
for ingress RBv and those 6 tree. You don't need entries for RBv and 8
tree, which wastes RPFC state. And if you only have entries for RBv
and less than 6 trees, some TRILL Data packets will be improperly
discarded due to the RPFC.

Thanks,
Donald
=============================
 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
 155 Beaver Street, Milford, MA 01757 USA
 d3e3e3@gmail.com

> Best Regards,
> Zhai Hongjun
> """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
> Protocol Development Dept.VI, Central R&D Institute, ZTE Corporation
> No. 68, Zijinghua Road, Yuhuatai District, Nanjing, P.R.China, 210012
>
> Zhai Hongjun
>
> Tel: +86-25-52877345
> Email: zhai.hongjun@zte.com.cn
> """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
>
>
>
>
> Donald Eastlake <d3e3e3@gmail.com>
> 发件人:  trill-bounces@ietf.org
>
> 2012-10-13 23:15
>
> 收件人
> trill@ietf.org
> 抄送
> 主题
> [trill] Comments on draft-ietf-trill-cmt-00
>
>
>
>
>
> There are my personal comments on draft-ietf-trill-cmt-00. I suggest
> that after these and the few other comments have been handled, the -01
> version be WG Last Called.
>
> - Some acronyms need to be spelled out on first use.
>
> - I think Figure 1 and Figure 2 are a bit muddled and should be
> clarified to show separate connections from each RBk to each CEn. It
> is also not clear to me why "DRB" occurs in the figures and I think it
> should be dropped.
>
> - The draft should be clear that when doing the RPFC for a
> multi-destination TRILL Data packet ingressed with a virtual RBridge
> nickname, the RPFC must assume that the TRILL Data packet might use
> any of the trees that any of the RBk might use.
>
> - The could be problems if a virtual RBridge nickname was taken away
> by a real RBridge somewhere else in the campus that is higher priority
> to hold a nickname. Perhaps the draft should suggest that virtual
> RBridge nicknames are usually configured  and should be held with
> maximum priority with with configured or unconfigured priority ranges,
> as appropriate...
>
> - I think it should be possible to use the Affinity Sub-TLV to change
> the structure of multi-destination distribution trees in places other
> than at the edge. So they should be valid as long as they do not
> conflict even if the requested child is a real RBridge. But, of
> course, the requested child has to be an adjacent RBridge and the
> draft should say what it would mean if some RBridge lists, as a
> requested child for some tree, its parent in that tree.
>
> Thanks,
> Donald
> =============================
> Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
> 155 Beaver Street, Milford, MA 01757 USA
> d3e3e3@gmail.com
> _______________________________________________
> trill mailing list
> trill@ietf.org
> https://www.ietf.org/mailman/listinfo/trill
>