[Tsv-art] TSV-ART telechat review of draft-ietf-anima-stable-connectivity

Yoshifumi Nishida <nishida@sfc.wide.ad.jp> Wed, 10 January 2018 01:37 UTC

Return-Path: <nishida@sfc.wide.ad.jp>
X-Original-To: tsv-art@ietfa.amsl.com
Delivered-To: tsv-art@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 3A6FD12711D; Tue, 9 Jan 2018 17:37:26 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.91
X-Spam-Level:
X-Spam-Status: No, score=-1.91 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HTML_MESSAGE=0.001, SPF_PASS=-0.001, T_RP_MATCHES_RCVD=-0.01] autolearn=ham autolearn_force=no
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 WJ_Q6DhUmRJ6; Tue, 9 Jan 2018 17:37:23 -0800 (PST)
Received: from mail.sfc.wide.ad.jp (shonan.sfc.wide.ad.jp [IPv6:2001:200:0:8803::53]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id D9F26124C27; Tue, 9 Jan 2018 17:37:22 -0800 (PST)
Received: from mail-wm0-f48.google.com (mail-wm0-f48.google.com [74.125.82.48]) by mail.sfc.wide.ad.jp (Postfix) with ESMTPSA id 2EE062782B3; Wed, 10 Jan 2018 10:37:19 +0900 (JST)
Received: by mail-wm0-f48.google.com with SMTP id f140so23982255wmd.2; Tue, 09 Jan 2018 17:37:19 -0800 (PST)
X-Gm-Message-State: AKGB3mIRue/1hCncHpPbRPPC87geHo75YzeYqqifJXHheAAdhS2YvfsX Z47/156RiMOGzlZqVI7B53LLn0YqhveYePWA3vI=
X-Google-Smtp-Source: ACJfBou5LIsoA5jVL18fVOYNKBGkJhCgGfan3FzOCAKu0Te2ohvZDqgmgHAYmnji5+74Tn8YYZ3mouGgkgNuWltNWeI=
X-Received: by 10.28.50.67 with SMTP id y64mr13363201wmy.145.1515548237128; Tue, 09 Jan 2018 17:37:17 -0800 (PST)
MIME-Version: 1.0
Received: by 10.223.147.199 with HTTP; Tue, 9 Jan 2018 17:37:16 -0800 (PST)
From: Yoshifumi Nishida <nishida@sfc.wide.ad.jp>
Date: Tue, 09 Jan 2018 17:37:16 -0800
X-Gmail-Original-Message-ID: <CAO249ycJSfNrAg1QwajptZhxru2-g7ToQNXFq6er6ucehqXBXw@mail.gmail.com>
Message-ID: <CAO249ycJSfNrAg1QwajptZhxru2-g7ToQNXFq6er6ucehqXBXw@mail.gmail.com>
To: dreft-ietf-anima-stable-connectivity@ietf.org, tsv-art@ietf.org, anima@ietf.org
Content-Type: multipart/alternative; boundary="001a11412d7450699805626212c5"
Archived-At: <https://mailarchive.ietf.org/arch/msg/tsv-art/3jnMtVCVLWe15_FiUDmtGTrirmY>
Subject: [Tsv-art] TSV-ART telechat review of draft-ietf-anima-stable-connectivity
X-BeenThere: tsv-art@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: Transport Area Review Team <tsv-art.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tsv-art>, <mailto:tsv-art-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tsv-art/>
List-Post: <mailto:tsv-art@ietf.org>
List-Help: <mailto:tsv-art-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tsv-art>, <mailto:tsv-art-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 10 Jan 2018 01:37:26 -0000

I've reviewed this document as part of TSV-ART's ongoing effort to review
key IETF documents. These comments were written primarily for the transport
area directors, but are copied to the document's authors for their
information and to allow them to address any issues raised.When done at the
time of IETF Last Call, the authors should consider this review together
with any other last-call comments they receive. Please always CC tsv-art
@ietf.org if you reply to or forward this review.

Summary: This document is almost ready for publication, but several points
need to be clarified or updated.

1: In Section 2.1.5
"
  MPTCP (Multipath TCP -see [RFC6824]) is a very attractive candidate
  to automate the use of both data-plane and ACP and minimize or fully
  avoid the need for the above mentioned logical names to pre-set the
  desired connectivity (data-plane-only, ACP only, both).  For example,
  a set-up for non MPTCP aware applications would be as follows:

  DNS naming is set up to provide the ACP IPv6 address of network
  devices.  Unbeknownst to the application, MPTCP is used.  MPTCP
  mutually discovers between the NOC and network device the data-plane
  address and caries all traffic across it when that MPTCP subflow
  across the data-plane can be built.
"

It's not very clear to me how to archive this feature.
I think more explanation will be required.
As MPTCP resides in transport layer, I think it will be very tricky to know
which endpoint is used for ACP or for data-plane. Also, although MPTCP
can transmit application data to multiple destinations, it cannot
identify which part of data is for ACP or for data-plane as it doesn't
parse app data.

2: in Section 2.1.8

"
  Leverage and as necessary enhance MPTCP with automatic dual-
  connectivity: If an MPTCP unaware application is using ACP
  connectivity, the policies used should add subflow(s) via the
  data-plane and prefer them.
"

I think functions like controlling policies should be designed outside of
MPTCP such as middleware
between applications and transport layer, but the text is unclear about how
to enhance MPTCP.

Thanks,
--
Yoshi