Re: [spring] SRH scratch space (was Re: Question about SRv6 Insert function)

Robert Raszuk <robert@raszuk.net> Thu, 12 December 2019 19:22 UTC

Return-Path: <robert@raszuk.net>
X-Original-To: spring@ietfa.amsl.com
Delivered-To: spring@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 2749B120A21 for <spring@ietfa.amsl.com>; Thu, 12 Dec 2019 11:22:08 -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, HTML_MESSAGE=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=unavailable autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=raszuk.net
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 WEf6pvYuuzfW for <spring@ietfa.amsl.com>; Thu, 12 Dec 2019 11:22:05 -0800 (PST)
Received: from mail-qv1-xf33.google.com (mail-qv1-xf33.google.com [IPv6:2607:f8b0:4864:20::f33]) (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 26482120152 for <spring@ietf.org>; Thu, 12 Dec 2019 11:22:05 -0800 (PST)
Received: by mail-qv1-xf33.google.com with SMTP id k10so1408980qve.7 for <spring@ietf.org>; Thu, 12 Dec 2019 11:22:05 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=raszuk.net; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=1Baz2YLRAbPnaTi27nt9G+o5Jv3nZWN2ApwEswefbME=; b=cJkcR34NGcBTA+jjQ+6ps4/J/DvdyVHzoCzu6Lh2UDVlYKs6O84sbMJdEUlocNr836 BsRaCDFBm75pT3AkGKMDUqVwlBvReDiJICr3leixTO7rZBocagx5yti1G9UwjpzNo8o9 8/Kk3tMpU1fg3LltczBFGscVrsoAT6B5C+I5Pw9UnkR5opue1tYx+M24Qt9T498t576y WOzvjzT6PSAyXTPyB7R+Cy6OKzSV06YyuGoE3/4facJzH1RzutEzuRn222HLxP4EDHxI UfsqMRBBtBOY9XnU3H+QG/eCCjeBtniQvGDkFWn+UWLw8Vc9D/077w1CT3Nwt5Rieok1 S7Ug==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=1Baz2YLRAbPnaTi27nt9G+o5Jv3nZWN2ApwEswefbME=; b=jjq7JTGwmQxnfyGGogOgALrZuvpN006oHVfJoNe/PtmfwwL59JIFkguoYIj8Nx971Z GjDSpe2hAfvKOoBcfCVkLWS9RJvQ3ZcgyFPYqqfWCDM9wI8IoLXVIuQ5fp9S83yxwAS9 K64GcX/sntodPxw36EA3C28l4NUcsrUw2dO5l24sTy6+7CuqcH/ik/uvQ7Dx9prnUhfz ZS44mf70EidoBXSg0ESzaIeyMbg8COLGnJNyQoZgnwO2QmIjAI+2w1ufjvVtGYBRPMmh SAa3b4qoKyFK7Xe2mdaQr0VKOyPA1bnU3g0AiBim5pDOKqzXf17RTMeiNcA+dEsLtjFb GFIw==
X-Gm-Message-State: APjAAAVM0AIY/m4CqK5vh4DefZ2BdGurhOrjleWUlVnPGMjdlPN5hb7i g1izONoa8EhR8UaSUxBBwLNnI+C573M4dan0vC5XFQ==
X-Google-Smtp-Source: APXvYqwiEwJSv7xdW+rJKFu24x2cqYQHKjoocGHeUlTpt0j45RiTdIAuuvgCyHfR7Ug0XFG8fQK2qssI+uYc4gAdlgI=
X-Received: by 2002:a0c:efc4:: with SMTP id a4mr8527875qvt.230.1576178523880; Thu, 12 Dec 2019 11:22:03 -0800 (PST)
MIME-Version: 1.0
References: <HK0PR03MB3970C6DCC635E7CD802D65FDFCBD0@HK0PR03MB3970.apcprd03.prod.outlook.com> <BYAPR05MB54636A2332FED916A26A6F14AEBD0@BYAPR05MB5463.namprd05.prod.outlook.com> <3e31873a-278a-2154-0e71-4d820bba323d@gont.com.ar> <4012D854-2F10-4476-951D-FFFE73C5083C@gmail.com> <cb2f56f8-acdc-d68d-0878-9609cb3d7b1b@gont.com.ar> <28214_1567694772_5D711FB4_28214_238_1_53C29892C857584299CBF5D05346208A48BFA9F3@OPEXCAUBM43.corporate.adroot.infra.ftgroup> <129bbb32-0f14-b799-430c-8f76fb6b1279@gont.com.ar> <1824_1575998223_5DEFD30F_1824_112_1_53C29892C857584299CBF5D05346208A48D24EBD@OPEXCAUBM43.corporate.adroot.infra.ftgroup> <4384c08a-65f5-dbfb-85c7-8365feba9662@gmail.com> <CAOj+MME1+JXth8m4U_E5R6VLvurVR_y_DQvOBy7JmGxHZp7T=Q@mail.gmail.com> <CAMGpriV8BFjOed_-QJYEZc_BANvEuc1hRgYjSdaVUYygVzPj+Q@mail.gmail.com> <CAOj+MMHCA+=9zv_UJAF3gC6R1TWKb6LQJxaGsrRa0N7Amdxrww@mail.gmail.com> <f86050ed-dc45-7b2f-3098-94173efdf949@gmail.com> <CAOj+MMHCJPPiA-znmkvi3VfES181_VWMsK+3ecESnO1bFo5iXg@mail.gmail.com> <CABNhwV18K-_J4CwAGrDVd-Qd-vAH5jgKn-Tqp1fG1io-D8q0rg@mail.gmail.com>
In-Reply-To: <CABNhwV18K-_J4CwAGrDVd-Qd-vAH5jgKn-Tqp1fG1io-D8q0rg@mail.gmail.com>
From: Robert Raszuk <robert@raszuk.net>
Date: Thu, 12 Dec 2019 20:21:54 +0100
Message-ID: <CAOj+MMENXm2HomURZYrjoYOnD9ySk6Nzs=WOqRC-dDjPn5=i-Q@mail.gmail.com>
To: Gyan Mishra <hayabusagsm@gmail.com>
Cc: "6man@ietf.org" <6man@ietf.org>, Brian E Carpenter <brian.e.carpenter@gmail.com>, Fernando Gont <fernando@gont.com.ar>, Ron Bonica <rbonica=40juniper.net@dmarc.ietf.org>, Suresh Krishnan <suresh.krishnan@gmail.com>, draft-ietf-spring-srv6-network-programming <draft-ietf-spring-srv6-network-programming@ietf.org>, draft-voyer-6man-extension-header-insertion <draft-voyer-6man-extension-header-insertion@ietf.org>, "spring@ietf.org" <spring@ietf.org>
Content-Type: multipart/alternative; boundary="00000000000004eccc059986a9e0"
Archived-At: <https://mailarchive.ietf.org/arch/msg/spring/ZmS5QQ1DZRv89dIibuG7P_CNyKI>
Subject: Re: [spring] SRH scratch space (was Re: Question about SRv6 Insert function)
X-BeenThere: spring@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Source Packet Routing in NetworkinG \(SPRING\)" <spring.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/spring>, <mailto:spring-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/spring/>
List-Post: <mailto:spring@ietf.org>
List-Help: <mailto:spring-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/spring>, <mailto:spring-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 12 Dec 2019 19:22:12 -0000

Thank you.

Yes this draft can work with controller, but can also work without one.

Please observe that I am (re)using BGP extension to propagate control plane
information which can originate from any network element not necessarily a
central controller. Nevertheless using it with conjunction of some oracle
to optimize global network TE or steer some packets towards selected SFCs
is by all means a sound approach.

Kind regards,
Robert

On Thu, Dec 12, 2019 at 7:54 PM Gyan Mishra <hayabusagsm@gmail.com> wrote:

>
>
> On Wed, Dec 11, 2019 at 3:37 AM Robert Raszuk <robert@raszuk.net> wrote:
>
>> Hi Brian,
>>
>> > Each SR node (Segment Endpoint) is effectively applying new IPv6 encap
>>> so is already doing an insertion of new SRH
>>>
>>> That isn't "insertion" in the sense of draft-voyer.
>>
>>
>> Correct. But we are not discussing draft-voyer here.
>>
>> I think recent mail threads prove that it is much better to discuss one
>> topic at a time rather then mix three different and pretty orthogonal
>> "issues" interchangeably.
>>
>>
>>>  . It's prepending an extra layer of encapsulation, which is indeed just
>>> fine and I don't think anyone here is objecting to it. The spring draft
>>> currently uses (IMHO) imprecise language, even in its pseudo-code, but if
>>> all it's doing is describing successive layers of encapsulation that's fine
>>> too. Wasted bytes perhaps, but that isn't an IETF problem.
>>
>>
>> Great that we agree.
>>
>>
>>> Whether prepending new headers, each with their own SRH, is the best way
>>> of doing service-based traffic engineering is another question. Having just
>>> reviewed draft-ietf-bess-nsh-bgp-control-plane for Gen-ART, I do believe
>>> there's more than one possible approach.
>>>
>>
>> 100% agreed. In fact as you may have seen I have another non data plane,
>> but control plane proposal posted:
>> https://tools.ietf.org/html/draft-raszuk-teas-ip-te-np-00
>>
>> Kind regards,
>> R.
>>
>
>   Robert
>
>     Your ip-te teas WG draft sounds like a fine solution and maybe can be
> used in conjunction with Gen-ART sfc draft in centralized SDN controller
> based architecture.  So with draft is pulls the control plane function or
> Ti-LFA and SR-TE and/or binding SID policies into control plane nodes which
> could be the PEs eliminating SRH state in the P core.  So this in essence
> using this feature we would save on overhead bytes with the additional 6in6
> encap plus SRH state.
>
> Warm regards,
>
> Gyan
>
>>
>> --------------------------------------------------------------------
>> IETF IPv6 working group mailing list
>> ipv6@ietf.org
>> Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6
>> --------------------------------------------------------------------
>>
> --
>
> Gyan S. Mishra
>
> IT Network Engineering & Technology
>
> Verizon Communications Inc. (VZ)
>
> 13101 Columbia Pike FDC1 3rd Floor
>
> Silver Spring, MD 20904
>
> United States
>
> Phone: 301 502-1347
>
> Email: gyan.s.mishra@verizon.com
>
> www.linkedin.com/in/networking-technologies-consultant
>
>