Return-Path: 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 2DEF012A208; Mon, 27 Feb 2017 08:43:01 -0800 (PST) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -1.998 X-Spam-Level: X-Spam-Status: No, score=-1.998 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, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com 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 mWO0ouloDjco; Mon, 27 Feb 2017 08:42:59 -0800 (PST) Received: from mail-ot0-x234.google.com (mail-ot0-x234.google.com [IPv6:2607:f8b0:4003:c0f::234]) (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 EE88412A1F8; Mon, 27 Feb 2017 08:42:58 -0800 (PST) Received: by mail-ot0-x234.google.com with SMTP id i1so14951451ota.3; Mon, 27 Feb 2017 08:42:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=iXDM4mThDU4p/V6Gz2RooOCS383KYRmln6GjhPSWujQ=; b=nAUXkfJoZ/sJ/V6aOfEINzJ/c10O1v1/MBYCJN4QbpY1g8QYIdRZN0epwzfbDl7qCX nQ7WtDsRuIeqn6ga9KYL5yD+dqUHIFNOcBsrAAPYCf/CMfUfQSrcWK8HTgexKCu7glE0 lvI4KGl/l7WQpXmvitoQ7OMR6CuD452t8hsm4Up1RHnCniUZhhMgng0Yq39Pz1+G9go+ DYuxnU7LJ2KLlAVuVydRx91jRfrrzE8J74di9UiqTFEpdrpMsxgcr5IoFnQcn52BuBf1 KSxpa++ag3EE7uSynSWhUvI1aR8dFLHKpr9gakVg1vTsh5DEteU/ZxmeuDKQI4XOu4Dr 2Hjg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=iXDM4mThDU4p/V6Gz2RooOCS383KYRmln6GjhPSWujQ=; b=QuwMpf9ue2sB1v8hmYu0ioBbbhR0eL7/2p28gJ6c8VO2kU4sv6YoSOmSE8vfjvFC/a S47oMOH5I3FyeAu6BYpoKOOBM3WqOjSWlGc1kFf8/PC6Aot32kOv7Fo4YmGZ11ffwCeq NybEBfcw6v8iClhS13+l+L1dKh7Ijbhct0PsYvQOpeKhn8YcZG//586o7wV8rTnwxRVT M9Is2XOAOXT9SfLCwoLSoVkl5XTFZImrn1CUQ64t2fQS3xPQuDlEsSp5ZCSfuUdmlQTa T+RuN7U0iadLu95nBRDHU601bZgh3z3O1XeIbwsuvwtZeQ41tfCEOurA+JUy3Qohm5pe B0ZA== X-Gm-Message-State: AMke39mMCZLJ3hFkc7r0lIxQ+SQovkCeSX5GkBbpsvhdbVY5e+k8ayCCbEWsWSs0neKau9FkWy28C29Pc8Q4ig== X-Received: by 10.157.59.72 with SMTP id z66mr8225365otb.191.1488213778288; Mon, 27 Feb 2017 08:42:58 -0800 (PST) MIME-Version: 1.0 Received: by 10.182.52.7 with HTTP; Mon, 27 Feb 2017 08:42:37 -0800 (PST) In-Reply-To: <8FA0B47D-32C0-41D0-BBDD-35F430DC44EE@nokia.com> References: <8FA0B47D-32C0-41D0-BBDD-35F430DC44EE@nokia.com> From: "Andrew G. Malis" Date: Mon, 27 Feb 2017 11:42:37 -0500 Message-ID: To: "Bocci, Matthew (Nokia - GB)" Content-Type: multipart/alternative; boundary=001a1141abfc9ad759054985c52b Archived-At: Cc: "rtg-dir@ietf.org" , "draft-ietf-trill-transport-over-mpls@ietf.org" , "trill@ietf.org" Subject: Re: [trill] [RTG-DIR] Routing Area Directorate QA review of draft-ietf-trill-transport-over-mpls-02 X-BeenThere: trill@ietf.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: "Developing a hybrid router/bridge." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 27 Feb 2017 16:43:01 -0000 --001a1141abfc9ad759054985c52b Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable I=E2=80=99ve got some comments on Matthew=E2=80=99s review, inline. On Mon, Feb 27, 2017 at 10:44 AM, Bocci, Matthew (Nokia - GB) < matthew.bocci@nokia.com> wrote: > Routing Area Directorate QA review of draft-ietf-trill-transport- > over-mpls-02 > > > > Hi, > > > > I have been assigned the QA reviewer for this draft. The general > guidelines for QA reviews > > can be found at: > > https://trac.ietf.org/trac/rtg/wiki/RtgDirDocQa > > > > These state: > > > > "When reviewing a draft at WG Adoption, the QA Reviewer should > > determine whether the draft is readable, understandable, makes sense > > and is a good start for a WG draft. Any issues the QA Reviewer finds > > are written down, sent to the mailing list and discussed for future > > versions" > > > > Here is my review of this draft: > > > > ** Summary. > > Generally, the draft is well written - thank you. I have a few minor > comments below, > > mostly related to the relationship between TRILL over MPLS and establishe= d > VPLS mechanisms. > > > > ** Is the draft readable? > > > > Yes. There are a few minor grammatical errors and it would help if the > draft was proof-read > > to weed-out these. An example is: > > Abstract > > "..that are separated by MPLS provider network." > > s/by MPLS/by an MPLS > > > > > > ** Is the draft understandable? > > > > Yes, provided the reader is familiar with TRILL, MPLS and VPLS. > > > > ** Does it make sense? > > I think it is mostly clear, but I have a few comments, as follows: > > > > Section 3.4. MPLS encapsulation for VPLS model > > > > "Use of VPLS [RFC4762] to interconnect TRILL sites requires no changes to > > a VPLS implementation, in particular the use of Ethernet pseudowires > > between VPLS PEs. A VPLS PE receives normal Ethernet frames from an > > RBridge (i.e., CE) and is not aware that the CE is an RBridge device. As > > a result, an MPLS-encapsulated TRILL packet within the MPLS network will > > use the format illustrated in Appendix A of [RFC7173]." > > > > It doesn't look like the encapsulation shown in Appendix A of > > RFC7173 takes account of the case where PBB VPLS [RFC7041] is used in the > provider's > > MPLS network, but I would have thought this would still be a valid VPLS > type to transport > > TRILL. It might be worth qualifying your reference with some text to stat= e > that > > this is just an example in the non-PBB case. > Andy: As the author of this paragraph, I agree with Matthew=E2=80=99s comme= nt. We can change the last sentence to say: "As an example, an MPLS-encapsulated TRILL packet within the MPLS network will use the format illustrated in Appendix A of [RFC7173] for the non-PBB case, or in the PBB case, with the additional header fields illustrated in [RFC7041]." > > Section 4.1.1: > > "TIR devices are a superset of the VPLS-PE devices defined in [RFC4026] > with the > > additional functionality of TRILL." > > Is this really true? Later you state that TIRs use PPP PWs, not the > Ethernet PWs used in > > VPLS. It is also not clear if TRILL needs some of the LDP or BGP signalin= g > extensions > > used for VPLS. Wouldn't it be cleaner just to define a TIR as a new kind > of PE? > Andy: I also agree with this comment. > > > Section 6. VPTS Model Versus VPLS Model > > "An issue with the above rule is that if a pseudowire between PEs fails, > > frames will not get forwarded between the PEs where pseudowire went > > down." > > > > I think this is only true for a simple full mesh VPLS where there are not > other protection > > mechanisms. I am not sure this is applicable to H-VPLS with PW redundancy= , > for example, > > which I think is likely to be a widespread deployment case for the VPLS > model of TRILL > > over MPLS. > Andy: I agree. In addition, see section 4.4 of RFC 4742, which allows the use of spanning tree in a VPLS network to provide redundancy in the case of a failure in the VPLS. > > Best regards > > Matthew > Cheers, Andy --001a1141abfc9ad759054985c52b Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I=E2=80=99ve got some comments on Matthew=E2=80=99s review= , inline.

On Mon, = Feb 27, 2017 at 10:44 AM, Bocci, Matthew (Nokia - GB) <= ;matthew.bocci= @nokia.com> wrote:

Routing Area Director= ate QA review of draft-ietf-trill-transport-over-mpls-02=

=C2=A0<= /span>

Hi,

=C2=A0<= /span>

I have been assigned = the QA reviewer for this draft. The general guidelines for QA reviews

can be found at:

https://trac.ietf.= org/trac/rtg/wiki/RtgDirDocQa

=C2=A0<= /span>

These state:

=C2=A0<= /span>

=C2=A0 "When rev= iewing a draft at WG Adoption, the QA Reviewer should<= /p>

=C2=A0 determine whet= her the draft is readable, understandable, makes sense=

=C2=A0 and is a good = start for a WG draft. Any issues the QA Reviewer finds=

=C2=A0 are written do= wn, sent to the mailing list and discussed for future<= /p>

=C2=A0 versions"=

=C2=A0<= /span>

Here is my review of = this draft:

=C2=A0<= /span>

** Summary.=

Generally, the draft = is well written - thank you. I have a few minor comments below,

mostly related to the= relationship between TRILL over MPLS and established VPLS mechanisms.

=C2=A0<= /span>

** Is the draft reada= ble?

=C2=A0<= /span>

Yes. There are a few = minor grammatical errors and it would help if the draft was proof-read

to weed-out these. An= example is:

Abstract

"..that are sepa= rated by MPLS provider network."

s/by MPLS/by an MPLS<= u>

=C2=A0<= /span>

=C2=A0<= /span>

** Is the draft under= standable?

=C2=A0<= /span>

Yes, provided the rea= der is familiar with TRILL, MPLS and VPLS.

=C2=A0<= /span>

** Does it make sense= ?

I think it is mostly = clear, but I have a few comments, as follows:

=C2=A0<= /span>

Section 3.4. MPLS enc= apsulation for VPLS model

=C2=A0<= /span>

"Use of VPLS [RF= C4762] to interconnect TRILL sites requires no changes to

a VPLS implementation= , in particular the use of Ethernet pseudowires

between VPLS PEs. A V= PLS PE receives normal Ethernet frames from an

RBridge (i.e., CE) an= d is not aware that the CE is an RBridge device. As

a result, an MPLS-enc= apsulated TRILL packet within the MPLS network will

use the format illust= rated in Appendix A of [RFC7173]."

=C2=A0<= /span>

It doesn't look l= ike the encapsulation shown in Appendix A of

RFC7173 takes account= of the case where PBB VPLS [RFC7041] is used in the provider's

MPLS network, but I w= ould have thought this would still be a valid VPLS type to transport

TRILL. It might be wo= rth qualifying your reference with some text to state that

this is just an examp= le in the non-PBB case.


<= div>Andy: As the author of this paragraph, I agree with Matthew=E2=80=99s c= omment. We can change the last sentence to say:

"As an example, an MPLS-encapsulated TRILL packet within the MPLS n= etwork will
use the format illustrated in Appendix A of [RFC7173]= for the non-PBB case, or
in the PBB case, with the additio= nal header fields illustrated in [RFC7041]."

=C2=A0<= /span>

Section 4.1.1:=

"TIR devices are= a superset of the VPLS-PE devices defined in [RFC4026] with the

additional functional= ity of TRILL."

Is this really true? = Later you state that TIRs use PPP PWs, not the Ethernet PWs used in

VPLS. It is also not = clear if TRILL needs some of the LDP or BGP signaling extensions

used for VPLS. Wouldn= 't it be cleaner just to define a TIR as a new kind of PE?


Andy: I also agree with this com= ment.
=C2=A0

=C2=A0<= /span>

Section 6. VPTS Model= Versus VPLS Model

"An issue with t= he above rule is that if a pseudowire between PEs fails,

frames will not get f= orwarded between the PEs where pseudowire went

down."=

=C2=A0<= /span>

I think this is only = true for a simple full mesh VPLS where there are not other protection

mechanisms. I am not = sure this is applicable to H-VPLS with PW redundancy, for example,

which I think is like= ly to be a widespread deployment case for the VPLS model of TRILL

over MPLS.

=

Andy: I agree. In addition, se= e section 4.4 of RFC 4742, which allows the use of spanning tree in a VPLS = network to provide redundancy in the case of a failure in the VPLS.


=

=C2=A0<= /span>

=C2=A0Best regards

=

=C2=A0Matthew<= /p>


Cheers,
=
Andy
=C2=A0

--001a1141abfc9ad759054985c52b--