Re: [Teas] I-D Action: draft-nsdt-teas-transport-slice-definition-03.txt

["Rokui, Reza (Nokia - CA/Ottawa)" <[e-mail]>]

Thanks Joel for your comments.

Please see inline for TSRE.



Reza





On 2020-07-12, 11:59 PM, "Teas on behalf of Joel Halpern" <[e-mail] on behalf of [e-mail]> wrote:



    My thanks to the design team for the update to this document.  It is

    much improved.



    I a  unable to understand the third paragraph of section 4.1.2.  I do

    not know what maximum occupancy refers to.  It seems to be talking about

    some kind of notion of objectives applying to subsets of traffic within

    a slice.  But I can't tell.



    Appendix A.1 is labeled as discussion, and as such appears to be trying

    to be informative rather than normative.  However, the last paragraph of

    introduces things a customer may ask for (i.e. SLOs) that are not

    described in the rest of the document, and do not actually seem to me to

    be appropriate.  I wowuld ask that the last paragraph of section A.1 be

    stricken.



    Some minor comments:



    At one point the SLA is defined (I believe reasonably)as the contract

    5that describes the SLOs with the consequences for missing them.  Then

    in section 4.1 it says "all SLOs combine to form the SLA".  Believe you

    mean "form the objective portion of the SLA"  or "contribute to the SLA"

    or something, since the contractual and consequence aspects of the SLA

    are outside of the SLOs?



    Given that availability is defined in terms of the other SLOs (quite

    reasonable) and that some of those may not be directly measurable), it

    seems that availability should itself be considered indirectly measurable?



    nit - Given that the earlier text says that this is only an initial

    list, there is no need to include a bullet in the aspects that says

    "Other objectives could be specified".  It is true.  But has already

    been stated above.



    In section 4.2 on transport service endpoints, the text seems to say

    that an endpoint has a specific kind of connectivity (P2P, P2MP, ...).

    It seems perfectly valid for a single TSE to be using both P2P and P2MP

    communication.  It seems rather odd to have to consider it to be two

    TSEs.  From later text, it is the slice, not the endpoint, which as a

    particular connectivity type.



    I wonder if the "Transport Slice Realization endpoint" is useful?  Given

    that many things are in both the sample TSE list and the sample TSRE

    list, it is going to be hard to tell them apart.  And as far as I can

    tell, the TSRE is internal to the transport, and therefore outside the

    scope of this document?  The differentiation in the diagram that follows

    the description does not seem to line up with the description, and

    leaves me more confused.

[Reza]

As mentioned in draft, Transport slice realization endpoints (TSRE) are allocated and

assigned by the network controller during the realization of a  transport slice and are technology-specific, i.e. they depend on the

network technology used during the transport slice realization.

Depends on the definition of the transport slice, Transport Slice endpoints (TSE) and TSRE might be very similar but their object models are different.

Please also see the following draft which addresses the modeling of the transport slice realization:

  *   draft-liu-teas-transport-network-slice-yang-01

In summary, TRSE are assigned during the transport slice realization and will be communicated from TSC NBI to higher system “Transport slice Customer” and identifies how a transport slice is realized in the network.

We will add more clarification to the draft.



    Yours,

    Joel



    On 7/12/2020 10:49 PM, [e-mail] wrote:

    >

    > A New Internet-Draft is available from the on-line Internet-Drafts directories.

    >

    >

    >          Title           : IETF Definition of Transport Slice

    >          Authors         : Reza Rokui

    >                            Shunsuke Homma

    >                            Kiran Makhijani

    >                            Luis M. Contreras

    >                            Jeff Tantsura

    >         Filename        : draft-nsdt-teas-transport-slice-definition-03.txt

    >         Pages           : 21

    >         Date            : 2020-07-12

    >

    > Abstract:

    >     This document describes the definition of a slice in the transport

    >     networks and its characteristics.  The purpose here is to bring

    >     clarity and a common understanding of the transport slice concept and

    >     describe related terms and their meaning.  It explains how transport

    >     slices can be used in combination with end to end network slices, or

    >     independently.

    >

    >

    > The IETF datatracker status page for this draft is:

    > https://datatracker.ietf.org/doc/draft-nsdt-teas-transport-slice-definition/

    >

    > There are also htmlized versions available at:

    > https://tools.ietf.org/html/draft-nsdt-teas-transport-slice-definition-03

    > https://datatracker.ietf.org/doc/html/draft-nsdt-teas-transport-slice-definition-03

    >

    > A diff from the previous version is available at:

    > https://www.ietf.org/rfcdiff?url2=draft-nsdt-teas-transport-slice-definition-03

    >

    >

    > Please note that it may take a couple of minutes from the time of submission

    > until the htmlized version and diff are available at tools.ietf.org.

    >

    > Internet-Drafts are also available by anonymous FTP at:

    > ftp://ftp.ietf.org/internet-drafts/

    >

    >

    > _______________________________________________

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    > Internet-Draft directories: http://www.ietf.org/shadow.html

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