Re: [Teas] Thoughts about draft-nsdt-teas-ietf-network-slice-definition and isolation

Joel Halpern Direct <jmh.direct@joelhalpern.com> Tue, 17 November 2020 10:05 UTC

Return-Path: <jmh.direct@joelhalpern.com>
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 B335F3A0DEB; Tue, 17 Nov 2020 02:05:40 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.099
X-Spam-Level:
X-Spam-Status: No, score=-2.099 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, NICE_REPLY_A=-0.001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=joelhalpern.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 FpwOMZ1YJJSk; Tue, 17 Nov 2020 02:05:39 -0800 (PST)
Received: from maila2.tigertech.net (maila2.tigertech.net [208.80.4.152]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 500D63A0DEA; Tue, 17 Nov 2020 02:05:39 -0800 (PST)
Received: from localhost (localhost [127.0.0.1]) by maila2.tigertech.net (Postfix) with ESMTP id 4Cb1m30nx2z6G90L; Tue, 17 Nov 2020 02:05:39 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelhalpern.com; s=2.tigertech; t=1605607539; bh=mGTiVrrVvPeUN6Xv3dlewgIOeP4XqLFXWwGCZPtoAds=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=SAvCOWYQ+uLMViLf88kmtzeaC+OXvIwF4R/iYqrHqjHN1Qgb6ewh6s6wAFsjdzDo9 Owcuc3qttFtosiT7qV7z6gem9Yxy+kXJf3a0OjXcIuktBHOu9xCv1LgHCF2JrxKm2x ZThh8BVIRc9JfbMsNA9kPpLYiYB+q9iiyigsM2c0=
X-Quarantine-ID: <IqH_iWkSQHH1>
X-Virus-Scanned: Debian amavisd-new at a2.tigertech.net
Received: from [192.168.128.43] (unknown [50.225.209.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by maila2.tigertech.net (Postfix) with ESMTPSA id 4Cb1m2337Jz6GCkm; Tue, 17 Nov 2020 02:05:38 -0800 (PST)
To: Stewart Bryant <stewart.bryant@gmail.com>
Cc: teas@ietf.org, draft-nsdt-teas-ietf-network-slice-definition@ietf.org
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> <a9d968ed-90af-4889-8cc8-bc57b76edbf3@Spark> <879FFB4D-3E9B-498C-BF40-B30252A8F273@gmail.com>
From: Joel Halpern Direct <jmh.direct@joelhalpern.com>
Message-ID: <d91f339b-ca19-cd1c-651f-45d8c8c8784d@joelhalpern.com>
Date: Tue, 17 Nov 2020 05:05:37 -0500
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.4.3
MIME-Version: 1.0
In-Reply-To: <879FFB4D-3E9B-498C-BF40-B30252A8F273@gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/teas/GOgqOoKu1TeDxFotgckYGS-j4Sg>
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 <teas.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/teas>, <mailto:teas-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/teas/>
List-Post: <mailto:teas@ietf.org>
List-Help: <mailto:teas-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/teas>, <mailto:teas-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 17 Nov 2020 10:05:41 -0000

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’t think mixing performance objectives with isolation is a great 
>> idea though,
>> an SLA doesn’t change because there’s 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 “ordinary” 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
> 
> 
>