From nobody Tue Nov 17 02:22:34 2020 Return-Path: X-Original-To: teas@ietfa.amsl.com Delivered-To: teas@ietfa.amsl.com Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 7F8DF3A0E50; Tue, 17 Nov 2020 02:22:32 -0800 (PST) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -1.097 X-Spam-Level: X-Spam-Status: No, score=-1.097 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, FREEMAIL_REPLY=1, HTML_MESSAGE=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=no 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 LkhcmGnZtsWl; Tue, 17 Nov 2020 02:22:30 -0800 (PST) Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) (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 9165D3A0E4F; Tue, 17 Nov 2020 02:22:30 -0800 (PST) Received: by mail-wm1-x331.google.com with SMTP id a3so2684334wmb.5; Tue, 17 Nov 2020 02:22:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:message-id:mime-version:subject:date:in-reply-to:cc:to :references; bh=ddh70PZD4pl4y30pHl3xUQ92BCIPnxdRT9rHThGc6Os=; b=CUuivSyO09AZ5KfyQg9Esn+2cwUzGJ/kaFnqpNaypW1Mc4RU7ImWEFDgjdu6ZrH0U1 nD2u6m+y/b6wbqD6naD7sn5N2iMnUEpFwTRSG4Eh/YeJQtOOW0h9v/cRvgW1qzg/DhWA KFGN9Thk7FpBssgQZQSNfg5rA7q18iN99CVPafUQyH23HBzlioMnRFtAbk0coJJ0n9jA R/STA555LEmIplkohdetTj1+M11MogzEyObMniQUO6TMLwd1nlRDPnXt07xYm2g/d04z Bxb2XTlj9zANO/7lKgPvhERkniqcLHo0t8zNIeQVP2FK8uC8jIDakm9AXihqZWvMgcAK jxIA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:message-id:mime-version:subject:date :in-reply-to:cc:to:references; bh=ddh70PZD4pl4y30pHl3xUQ92BCIPnxdRT9rHThGc6Os=; b=eyZI/+f6VPDWQHXfQmHlpg5x+M8m7y8FZ8+CUKBv3lKE0FL849OrlVeB7+58f1/0cG rF8bgx6fzeuiAA/N3rYJRbU0VyFrgXBNixpC5owiVg3p4Q0HCP9QPEOx6W8vyojgqKxr CMDYtqpJkA2RpPIPaJgzRbRDSJ0kBZ3mR1MA+KAouNQ0J7yJLrvnGfo8QwfVPzpbD2xc dyP/I5VUP2rZiVjOEqO9OkBkz8sE+5tcweZhclBhy5y6gIJNJLYtuiSSVqPa5uEL8S9e Zo2+fUDkYUFUK4kAF0R0/e4iYQ/GPQFXlnMWWZsI0Dz+zy+ax5bvkYY0zTjfy/RXvFpC X3WQ== X-Gm-Message-State: AOAM530KtU2kt0qqsR+NRtn7F60EN4AaK5YKI8XXC2DaQswtohP+DI4N rDyLjzYeq561NSrNuJ0Jilk= X-Google-Smtp-Source: ABdhPJyOBORFZIQN07tazT61tActj5tM7vfQJNJ8M7k7Kny5wfv2LVGqGBtGMP6EQUHAbilEFB8Ajw== X-Received: by 2002:a05:600c:d2:: with SMTP id u18mr3581669wmm.102.1605608548852; Tue, 17 Nov 2020 02:22:28 -0800 (PST) Received: from broadband.bt.com ([2a00:23c5:3395:c901:a9c3:7842:c90b:a6e1]) by smtp.gmail.com with ESMTPSA id f5sm27795343wrg.32.2020.11.17.02.22.27 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 17 Nov 2020 02:22:28 -0800 (PST) From: Stewart Bryant Message-Id: <4ACEF52F-BF99-4B45-BFA0-B0C221E4D4E7@gmail.com> Content-Type: multipart/alternative; boundary="Apple-Mail=_4F58019C-8CFC-4929-9E92-B084F675A914" Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.120.23.2.4\)) Date: Tue, 17 Nov 2020 10:22:27 +0000 In-Reply-To: Cc: Stewart Bryant , teas@ietf.org, draft-nsdt-teas-ietf-network-slice-definition@ietf.org To: Joel Halpern Direct References: <059e01d6b6ce$0f74a830$2e5df890$@olddog.co.uk> <9e8170c6-399b-e954-2abb-5e5f425f172a@joelhalpern.com> <13178999-9168-46fb-8455-36d4d5683a2e@Spark> <62c127a5-9230-d105-04b7-4b061fdd43c1@joelhalpern.com> <879FFB4D-3E9B-498C-BF40-B30252A8F273@gmail.com> X-Mailer: Apple Mail (2.3608.120.23.2.4) Archived-At: Subject: Re: [Teas] Thoughts about draft-nsdt-teas-ietf-network-slice-definition and isolation X-BeenThere: teas@ietf.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Traffic Engineering Architecture and Signaling working group discussion list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Nov 2020 10:22:33 -0000 --Apple-Mail=_4F58019C-8CFC-4929-9E92-B084F675A914 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 They are terms from the timing world where you look at a defect in terms = of its probability within a window within a larger observation period. = http://www.chronos.co.uk/files/pdfs/itsf/2008/Day2/Packet_TDEV_MTIE_and_MA= TIE_for_Estimating_the_Frequency_and_Phase_Stability_of_a_Packet_Slave_Clo= ck_(Antti_Pietilainen,_NSN).pdf = ITU define MTIE in G.810, but they are looking at a different class of = application (frequency transfer), but I think the concept translates = over here. If you look at slide 5 =E2=80=9CMTIE of a practical packet clock=E2=80=9D = you get the idea, but I think it needs expanding and applying to other = characteristics.=20 Now some of the error sources will be within the slice, but we also need = to worry about error sources induced from outside the slice. Best regards Stewart > On 17 Nov 2020, at 10:05, Joel Halpern Direct = wrote: >=20 > Stewart, I think you are raising an interesting question, but one = where I got lost part way through. >=20 > Can you elaborate one what you mean by "something analogous to MTIE = and TDEV to describe packet and network interaction". >=20 > Thank you, > Joel >=20 > On 11/17/2020 4:57 AM, Stewart Bryant wrote: >>> On 9 Nov 2020, at 23:37, Jeff Tantsura > wrote: >>>=20 >>> I don=E2=80=99t think mixing performance objectives with isolation = is a great idea though, >>> an SLA doesn=E2=80=99t change because there=E2=80=99s someone else = sharing infrastructure with you, it is well understood that any changes = within other customers should not affect you. >> No, but in this class of networks the interaction between customers = may be a lot more sensitive and detailed than we are used to. For = example the single metrics that we normally associate with delay and = jitter will likely become a mask in the same way that time and frequency = transfer system find necessary to completely specify and instrument the = behaviour of the subs system. We will likely need something analogous to = MTIE and TDEV to describe packet and network interaction. >> I therefore think it is useful to have an umbrella term for concept = and the set of metrics that are of necessity more complex and critical = than we are used to. >> A possible alternative umbrella term is network cross talk. We = understand the concept of crosstalk at the physical layer. The concept = here in terms of performance is that packets do not interact at the = micro level as well as the more normal macro level. >> However, isolation has other feature that we need to think about = under this umbrella, for example the need to only mix certain types of = traffic allow (or exclude) traffic to flow over certain geographies or = through nodes manufactured by certain countries. We do not have to agree = with these constraints, but we need to accept that they are becoming a = reality. >> Now we could achieve the above by buying dedicated fibre or dedicated = hardware, but that that does not support economies of scale. >> I would be fine with us using a term other than isolation, but I = think it is worthwhile highlighting that we are not in =E2=80=9Cordinary=E2= =80=9D SLA territory with this, but that it is more complex and more = detailed, and a top level term to group these characteristics is in my = view helpful. >> Best regards >> Stewart --Apple-Mail=_4F58019C-8CFC-4929-9E92-B084F675A914 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 They = are terms from the timing world where you look at a defect in terms of = its probability within a window within a larger observation period.

http://www.chronos.co.uk/files/pdfs/itsf/2008/Day2/Packet_TDEV_= MTIE_and_MATIE_for_Estimating_the_Frequency_and_Phase_Stability_of_a_Packe= t_Slave_Clock_(Antti_Pietilainen,_NSN).pdf

ITU define MTIE in G.810, but they are = looking at a different class of application (frequency transfer), but I = think the concept translates over here.

If you look at slide 5 =E2=80=9CMTIE of = a practical packet clock=E2=80=9D you get the idea, but I think it needs = expanding and applying to other characteristics. 

Now some of the error = sources will be within the slice, but we also need to worry about error = sources induced from outside the slice.

Best regards

Stewart



On 17 = Nov 2020, at 10:05, Joel Halpern Direct <jmh.direct@joelhalpern.com> wrote:

Stewart, I think you are raising an interesting question, but = one where I got lost part way through.

Can = you elaborate one what you mean by "something analogous to MTIE and TDEV = to describe packet and network interaction".

Thank you,
Joel

On = 11/17/2020 4:57 AM, Stewart Bryant wrote:
On 9 Nov = 2020, at 23:37, Jeff Tantsura <jefftant.ietf@gmail.com <mailto:jefftant.ietf@gmail.com>> wrote:

I don=E2=80=99t think mixing performance = objectives with isolation is a great idea though,
an SLA = doesn=E2=80=99t change because there=E2=80=99s someone else sharing = infrastructure with you, it is well understood that any changes within = other customers should not affect you.
No, = but in this class of networks the interaction between customers may be a = lot more sensitive and detailed than we are used to. For example the = single metrics that we normally associate with delay and jitter will = likely become a mask in the same way that time and frequency transfer = system find necessary to completely specify and instrument the behaviour = of the subs system. We will likely need something analogous to MTIE and = TDEV to describe packet and network interaction.
I = therefore think it is useful to have an umbrella term for concept and = the set of metrics that are of necessity more complex and critical than = we are used to.
A possible alternative umbrella term is = network cross talk. We understand the concept of crosstalk at the = physical layer. The concept here in terms of performance is that packets = do not interact at the micro level as well as the more normal macro = level.
However, isolation has other feature that we need = to think about under this umbrella, for example the need to only mix = certain types of traffic allow (or exclude) traffic to flow over certain = geographies or through nodes manufactured by certain countries. We do = not have to agree with these constraints, but we need to accept that = they are becoming a reality.
Now we could achieve the = above by buying dedicated fibre or dedicated hardware, but that that = does not support economies of scale.
I would be fine with = us using a term other than isolation, but I think it is worthwhile = highlighting that we are not in =E2=80=9Cordinary=E2=80=9D SLA territory = with this, but that it is more complex and more detailed, and a top = level term to group these characteristics is in my view helpful.
Best regards
Stewart

= --Apple-Mail=_4F58019C-8CFC-4929-9E92-B084F675A914--