Re: [Teas-ns-dt] Brief meeting notes

[Dhruv Dhody <[e-mail]>]

Hi Deborah,

I have a feeling that the disconnect can be highlighted by the following
figure from Jari's presentation from IETF 106 -

[image: image.png]

https://www.ietf.org/proceedings/106/slides/slides-106-teas-sessb-13-network-slicing-design-team-update-01.pdf

The RAN Slice and Core Slice were examples of things outside of IETF and
the strong assumption that the slice that we define in IETF (let's call it
IETF network slice) cannot be used by those. (This would be especially true
for the NBI YANG model that we are also defining.)

Because of that assumption, E2E network slice = IETF network slice +
other-slice(s). And that is how the need for a new term was justified. I
have a feeling not everyone agrees with this assumption and would be good
if we can clarify that!

I am not sure if this helps, I see new emails from Reza/Eric already, but
since I had typed this, let me just send it out anyways! Happy weekend!

Dhruv






On Fri, Sep 25, 2020 at 7:31 PM BRUNGARD, DEBORAH A <[e-mail]> wrote:

> Hi Reza,
>
> <AD hat off>
>
> It’s good to see not stuck on using a 3GPP term.
>
> As I think both Adrian and I noted before, I think we are approaching this
> with a different end model in mind. It depends how one wants to view this
> operationally. I’d say some basic operational requirements are:
> - ability for the E2E slice to traverse multiple domains
> - ability for each domain to efficiently provide the E2E slice the
> appropriate parameters - and this includes the ability to combine multiple
> E2E slices for supporting over the domain.
> - ability for the E2E slice to be identified and each domain needs to have
> the ability to identify the slice and the mapping in its domain
> - critical - it must not be assumed there is a one to one mapping between
> control/service entities and physical entities. As an operator, why I am so
> sensitive on the term transport, because it infers physical entities. Both
> ITU and IETF operators no longer look at our world as 1:1 “transport”
> pipes, it is a “network”, and that is critical for our operations to be
> intelligent.
>
> In ccamp and teas, we’ve modeled this in the past using the same term for
> the different domains (and ITU and ETSI do also) - this is why we are
> questioning why need now a different term within a domain. It complicates
> operationally.
>
> RFC4726 describes an E2E LSP and the multiple ways to support it across a
> domain. Each domain still uses the same term, LSP. And there are many
> models for supporting.
>
> As you were wondering on proprietary domains (an earlier thread), one
> could also use the ASON model, RFC4139. The E2E is a “call”. Each domain is
> a “call segment”, including the proprietary domain. Operationally, all
> domains know exactly the reference.
>
> Here, can use the term E2E network slice segments for the “connections” in
> the domain. Don’t forget in each domain, they will be supported by other
> network slices - hierarchical slices. So what you are referring to as
> connections may be a “network slice”. There needs to be an independence
> between control and realization in the network.
>
> Thanks,
> Deborah
>
> Sent from my iPhone
>
> On Sep 25, 2020, at 8:28 AM, Rokui, Reza (Nokia - CA/Ottawa) <
> [e-mail]> wrote:
>
> 
>
> John,
>
>
>
>                 >>>> Reza said that we couldn’t use the term ‘network
> slice’ because 3GPP uses the term ‘E2E network slice’.
>
>
>
> This is not correct and this is not what has been said. It has nothing to
> do with 3GPP.
>
> Whatever I mentioned was that an ‘E2E Network Slice” Is a concept between
> multiple users and for an operator to create it, it need to create one or
> more artifacts for various “Connections”.
>
> Calling these Connections “Network Slice” is not accurate as they are part
> of the “E2E Network Slice”
>
>
>
> Reza
>
>
>
>
>
> *From: *Teas-ns-dt <[e-mail]> on behalf of John E
> Drake <jdrake=[e-mail]>
> *Date: *Thursday, September 24, 2020 at 3:41 PM
> *To: *Jari Arkko <jari.arkko=[e-mail]>, "
> [e-mail]" <[e-mail]>
> *Cc: *"[e-mail]" <[e-mail]>, Lou Berger <
> [e-mail]>, "'BRUNGARD, DEBORAH A'" <[e-mail]>, Vishnu Pavan
> Beeram <vbeeram=[e-mail]>
> *Subject: *Re: [Teas-ns-dt] Brief meeting notes
>
>
>
> Hi,
>
>
>
> I just wanted to comment on some of the statements that were made during
> the conference call today.  I think it’s important that we have a written
> record rather than trying to respond during the conference call.
>
>
>
>    1. Reza said that we couldn’t use the term ‘network slice’ because
>    3GPP uses the term ‘E2E network slice’.  Obviously, ‘network slice’ is a
>    different term than ‘E2E network slice’ so this is nonsense.  Further, the
>    definition of the term ‘E2E network slice’ would appear to be the
>    concatenation of two or more ‘network slices’.
>    2. Kiran said that the network slicing was introducing an entirely new
>    concept to the IETF.  The last time I checked, there were roughly 20-30
>    drafts or RFCs on the topic of network slicing, all of which pre-date
>    anything the NSDT has published and all of which use the term ‘network
>    slicing’
>    3. Kiran said that ‘transport network’ was a common term in the IETF.
>    This is incorrect.  ‘Transport Network’ is an ITU term and the only time it
>    is used in the IETF is in support of the ITU’s use of MPLS.  This is
>    MPLS-TP (transport profile).
>    4. Kiran said that term ‘IETF network slice’ is not generic.  Why is
>    it important that the term we use be generic and why is this term not
>    generic?
>    5. Kiran said that the NBI was not a service definition.  I think this
>    is nonsense – otherwise, why do we have ‘service level objectives’?
>
>
>
> Further, any discussion of isolation should be in terms of the variation
> of an SLO parameter’s value, since this is the only thing a customer can
> measure as the instantiation of its ‘service’.  E.g., absolute isolation
> would mean that a given SLO parameter’s value is invariant.
>
>
>
> Yours Irrespectively,
>
>
>
> John
>
>
>
>
>
> Juniper Business Use Only
>
> *From:* Teas-ns-dt <[e-mail]> *On Behalf Of *Jari Arkko
> *Sent:* Thursday, September 24, 2020 12:34 PM
> *To:* [e-mail]
> *Subject:* [Teas-ns-dt] Brief meeting notes
>
>
>
> *[External Email. Be cautious of content]*
>
>
>
> *Situation*:
>
> - Documents not adopted as is
>
>
>
> *Process*:
>
> - we need to revise based on feedback and ask again
>
> - wait on framework until definitions agreed
>
> - interim on Oct 19
>
>
>
> *Main changes*:
>
> 1/ need to use a different term
>
> - Perhaps more about the name itself than its definition – but also have
> to worry about the latter. Maybe easier to discuss once the name is not
> objectionable?
>
> - We all recognize the feedback, and agree not to use transport network
> slice term
>
> - IETF network slice one contender, some resistance
>
> 2/ isolation
>
> - Need acceptable content, not just a placeholder
>
> - Need to understand which approach to use, though (Jari recommended
> explaining how the term relates to this work, perhaps some breakdown of the
> term as well)
>
>
>
> *Next steps*:
>
> - For each issue/change, a small team to look at it, provide some options,
> and analysis of the implications and tradeoffs in those options
>
> - Post early to main TEAS WG list, keep discussion ongoing
>
> - Jari can arrange a weekly call starting next week (again, posted to main
> list) for those who want to discuss in real-time. But useful only after the
> above two steps are done first.
>
> - Responsible people: on the name issue, the author team; on isolation
> Luis, Jie, and Jeff will work on it
>
> - Everyone else to stay active on list + comment and make counter
> proposals and additional analysis
>
>
>
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