Re: [spring] [Teas] More Discussion//RE: Re:Re: New term for the underlay construct used for slice realization

song.xueyan2@zte.com.cn Fri, 27 August 2021 03:19 UTC

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Subject: Re: [spring] [Teas] More Discussion//RE: Re:Re: New term for the underlay construct used for slice realization
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Hi all,






I would like to share my thoughts on the term discussion:


1. The term we talked is the underlay network construct that was used for IETF Network Slice delivery, right?


2. The underlay network construct may include a set of endpoints (which are not abstract but concret, specific ones)and its corresponding network resources.


3. Refer to 3GPP TS 23.501, I copied here,


Network Slice: A logical network that provides specific network capabilities and network characteristics.


Network Slice Instance: A set of Network Function instances and the required resources (e.g., compute, storage, and networking resources) which form a deployed Network Slice.


From this definition, it is not difficult to find that the realization of a specific network slice is through the selection and provision of network slice instances, also may use a specific network slice instance to identify some limited network functions and resources.


4. Corresponding to IETF term, the "IETF Network Slice" definition refer to the TEAS WG draft,


IETF Network Slice: A logical network topology connecting a number of endpoints using a set of shared or dedicated network resources that are used to satisfy specific Service Level Objectives (SLO).


It seems that there is no big difference or contradition between 3GPP and IETF definition on "Network Slice", back to the term we talked, what about to use "IETF Network Slice Instance" correspondingly? The concept of "IETF Network Slice" is abstract, the concept of "IETF Network Slice Instance" is concret and specific on the provision of underlay network resources required for "IETF Network Slice" service delivery. 


When we talked about hte relationship between "IETF Network Slice" with "IETF Netwrok Slice Instance", it may includes 1:N or N:1 (N>=1).


5. Besides, based on the front discussion, there seems many agreements on using network slice aggregation or network slice group to identify the needs for the mapping of one or more IETF Network Slice to a single slicing underlay network resources, we may add some other words to "IETF Network Slice Instance", such as IETF Network Slice Aggregation Instance, IETF Network Slice Group Instance, etc.?






Did I miss anything?






Best regards,


Xueyan














原始邮件



发件人:TarekSaad
收件人:Dongjie (Jimmy);John E Drake;Lizhenbin;TEAS WG;
抄送人:mpls@ietf.org;spring@ietf.org;龚立艳;draft-filsfils-sprin;draft-ali-teas-sprin;EXT-vishnupavan@gmail.com;Adrian Farrel;draft-decraene-mpls-;
日 期 :2021年08月25日 23:17
主 题 :Re: [Teas] More Discussion//RE: Re:Re: New term for the underlay construct used for slice realization


_______________________________________________
Teas mailing list
Teas@ietf.org
https://www.ietf.org/mailman/listinfo/teas

 

Hi Jie,


 


See Inline, [TS2].


 



From: Dongjie (Jimmy) <jie.dong@huawei.com>
 Date: Tuesday, August 24, 2021 at 11:16 AM
 To: Tarek Saad <tsaad.net@gmail.com>, John E Drake <jdrake@juniper.net>, Lizhenbin <lizhenbin@huawei.com>, TEAS WG <teas@ietf.org>
 Cc: spring@ietf.org <spring@ietf.org>, mpls@ietf.org <mpls@ietf.org>, 龚立艳 <gongliyan@chinamobile.com>, draft-filsfils-sprin <draft-filsfils-spring-srv6-stateless-slice-id@ietf.org>, draft-ali-teas-sprin <draft-ali-teas-spring-ns-building-blocks@ietf.org>, EXT-vishnupavan@gmail.com <vishnupavan@gmail.com>, Adrian Farrel <adrian@olddog.co.uk>, draft-decraene-mpls- <draft-decraene-mpls-slid-encoded-entropy-label-id@ietf.org>
 Subject: RE: [Teas] More Discussion//RE: Re:Re: New term for the underlay construct used for slice realization



Hi,


 


Please see comments inline with [Jie]:


 




From: Tarek Saad [mailto:tsaad.net@gmail.com] 
 Sent: Saturday, August 21, 2021 1:05 AM
 To: John E Drake <jdrake@juniper.net>; Lizhenbin <lizhenbin@huawei.com>; TEAS WG <teas@ietf.org>
 Cc: Dongjie (Jimmy) <jie.dong@huawei.com>; spring@ietf.org; mpls@ietf.org; 龚立艳 <gongliyan@chinamobile.com>; draft-filsfils-sprin <draft-filsfils-spring-srv6-stateless-slice-id@ietf.org>; draft-ali-teas-sprin <draft-ali-teas-spring-ns-building-blocks@ietf.org>; EXT-vishnupavan@gmail.com <vishnupavan@gmail.com>; Adrian Farrel <adrian@olddog.co.uk>; draft-decraene-mpls- <draft-decraene-mpls-slid-encoded-entropy-label-id@ietf.org>
 Subject: Re: [Teas] More Discussion//RE: Re:Re: New term for the underlay construct used for slice realization




 


Hi,


 


Comments inline.


 



From: John E Drake <jdrake@juniper.net>
 Date: Friday, August 20, 2021 at 9:33 AM
 To: Lizhenbin <lizhenbin@huawei.com>, TEAS WG <teas@ietf.org>
 Cc: Dongjie (Jimmy) <jie.dong@huawei.com>, spring@ietf.org <spring@ietf.org>, mpls@ietf.org <mpls@ietf.org>, 龚立艳 <gongliyan@chinamobile.com>, draft-filsfils-sprin <draft-filsfils-spring-srv6-stateless-slice-id@ietf.org>, draft-ali-teas-sprin <draft-ali-teas-spring-ns-building-blocks@ietf.org>, EXT-vishnupavan@gmail.com <vishnupavan@gmail.com>, Adrian Farrel <adrian@olddog.co.uk>, Tarek Saad <tsaad.net@gmail.com>, draft-decraene-mpls- <draft-decraene-mpls-slid-encoded-entropy-label-id@ietf.org>
 Subject: RE: [Teas] More Discussion//RE: Re:Re: New term for the underlay construct used for slice realization



Hi,


 


Comments inline.


 


Yours Irrespectively,


 


John



 


 


Juniper Business Use Only




From: Teas <teas-bounces@ietf.org> On Behalf Of Lizhenbin
 Sent: Thursday, August 19, 2021 1:05 PM
 To: TEAS WG <teas@ietf.org>
 Cc: Dongjie (Jimmy) <jie.dong@huawei.com>; spring@ietf.org; mpls@ietf.org; 龚立艳 <gongliyan@chinamobile.com>; draft-filsfils-sprin <draft-filsfils-spring-srv6-stateless-slice-id@ietf.org>; draft-ali-teas-sprin <draft-ali-teas-spring-ns-building-blocks@ietf.org>; EXT-vishnupavan@gmail.com <vishnupavan@gmail.com>; Adrian Farrel <adrian@olddog.co.uk>; Tarek Saad <tsaad.net@gmail.com>; draft-decraene-mpls- <draft-decraene-mpls-slid-encoded-entropy-label-id@ietf.org>
 Subject: [Teas] More Discussion//RE: Re:Re: New term for the underlay construct used for slice realization




 


[External Email. Be cautious of content]


 


Hi Folks,


 


The “new term” discussion has been lasted for a while, thanks to all who participated in the discussion.


 


So far it seems there are some rough consensus about this “new term” (maybe I am wrong) :


1. It is better to have a neutral term, which allows this underlay construct to be used for both network slice services and other types of services.


2. It seems “resource group” receives more support than other candidates.


 


[JD]  Making these conclusions is the co-chairs’ job.


 


[TS]: +1


 


Here I’d also like to share some considerations and doubts about the underlay construct used for slice realization:


1. Before this discussion happens, it seems many network slicing related drafts use “slice” in their terms which refer to this underlay construct. However, through this new term discussion, it seems most people indicate they prefer a neutral term than a slice specific term. Thus I expect the authors of the related drafts to provide more feedback about this point and indicate whether they agree with the choice of a neutral term.


 


2. As mentioned several times during the discussion, this underlay construct has both the topology and resource attributes. With the term “resource group”, it is clear that it is a set of network resources, then how about the topology attribute? Is the topology attribute also included in the “resource group”?


 


[JD]  There are two separate concepts:


 


1)      Resource Partition - a subset of an underlay network link's buffer/queuing/scheduling resources used to enable the underlay network to have finer grained control of its data plane.


 


2)      Combining these resource partitions into a topology in the underlay network, for which I was using the term 'partitioned underlay network topology'.


 


 


[TS]: I suggested appending network – i.e. “network resource partition” as more suitable to indicate resources are over an underlay “network” vs. a resource partition over a single link.


 


[Jie] While I understand the intent here is to indicate that the resource partitions are spread over the network, however “network resource partition” could be interpreted as “partition of network resources (e.g. buffer/queue/scheduling resources)”, which does not convey the information we need.


 


Perhaps a more explicit approach is to put network in the end: resource partitioned network (or sub-network), so that it is clear that the resource partitions are spread over the network with a sub-topology.


 


[TS2]: The “network” here is to define the “scope” of the resource group (or partition) and not connectivity. Hence, I favor “network” being as a prefix.


 


 


3. What is the intended scope of resource group? More specifically, is a point-to-point path or a P2MP path with a set of reserved network resource a resource group? In history, RSVP-TE was used to set up resource reserved point-to-point TE paths and P2MP TE paths. More recently, there is effort in DetNet WG on the mechanisms to set up deterministic data paths. Can these paths be considered as resource groups?  Can we further classify them into different P2P resource group, P2MP resource group, or MP2MP resource group?


 


[JD]  The connectivity constructs of a given IETF network slice service can be implemented in the underlay network using whatever technologies the provider wishes to use.  A given resource partition can support multiple connectivity constructs of any type.


 


[TS]: I agree here. Different connectivity types can be realized over the same network resource partition 


 


[Jie] Then my understanding is this underlay construct always provide any-to-any connectivity between the edge nodes, which can be used to deliver services with any connectivity type. Is this correct?


 


[TS2]: The resources may be connected (in different ways) to provide any type of connectivity.


 


4. A more subtle question is, what is the relationship between resource group and TE? Is resource group a construct under the TE architecture, or is there some overlap between them?


 


[JD]  Resource partitions just provide an enhanced underlay network topology to which a provider can apply TE if they so desire.


 


[TS]: TE can be done over the resources that a network resource partition can offer – for example, to optimally place paths over the remaining resources of network resource partition.


 


[Jie] This may be related to the definition of TE. Is resource partition or reservation one of the components of TE? I hope we can get some answer from 3272bis.


 


We used to define the TE-LSP as something with which we can specify the path and the set of resources reserved along the path. Following this, the underlay construct we are discussing can be used to specify the topology and the set of resources reserved in the topology.  If we call the TE-LSP a “TE path”, maybe we can call this underlay construct a “TE network” or “virtual TE network”. Then TE paths can be provisioned in the virtual TE network, just like how the TE paths are provisioned in the physical network.


 


[TS2]: AFAICS, the term we’re defining describes a set of resources in a network and, hence, it is orthogonal to the TE discussion.


 


Regards,


Tarek


 


Best regards,


Jie


 


Regards,


Tarek


 


Wish to learn your thoughts on these considerations and doubts.


 


 


 


Best Regards,


Robin


 


 


 


 


 


 



From: Lizhenbin 
 Sent: Tuesday, August 17, 2021 10:29 PM
 To: '龚立艳' <gongliyan@chinamobile.com>; draft-ali-teas-sprin <draft-ali-teas-spring-ns-building-blocks@ietf.org>; draft-filsfils-sprin <draft-filsfils-spring-srv6-stateless-slice-id@ietf.org>; draft-decraene-mpls- <draft-decraene-mpls-slid-encoded-entropy-label-id@ietf.org>
 Cc: Dongjie (Jimmy) <jie.dong@huawei.com>; spring@ietf.org; mpls@ietf.org; TEAS WG <teas@ietf.org>; EXT-vishnupavan@gmai <vishnupavan@gmail.com>; Adrian Farrel <adrian@olddog.co.uk>; Tarek Saad <tsaad.net@gmail.com>
 Subject: RE: Re:Re: [Teas] New term for the underlay construct used for slicerealization




 


Hi Liyan,


Sorry that I missed your new draft. Thanks for your feedback. It is helpful for us to have a common terminology.


 


Best Regards,


Robin


 


 


 


From: 龚立艳 [mailto:gongliyan@chinamobile.com] 
 Sent: Tuesday, August 17, 2021 4:48 PM
 To: Lizhenbin <lizhenbin@huawei.com>; draft-ali-teas-sprin <draft-ali-teas-spring-ns-building-blocks@ietf.org>; draft-filsfils-sprin <draft-filsfils-spring-srv6-stateless-slice-id@ietf.org>; draft-decraene-mpls- <draft-decraene-mpls-slid-encoded-entropy-label-id@ietf.org>
 Cc: Dongjie (Jimmy) <jie.dong@huawei.com>; spring@ietf.org; mpls@ietf.org; TEAS WG <teas@ietf.org>; EXT-vishnupavan@gmai <vishnupavan@gmail.com>; Adrian Farrel <adrian@olddog.co.uk>; Tarek Saad <tsaad.net@gmail.com>
 Subject: Re:Re: [Teas] New term for the underlay construct used for slicerealization


 

Hi All,

The draft-cheng-spring-srv6-encoding-network-sliceid[1] also provided a slice ID encoding solution.

And about the discussion, we are fine to follow the final decision of the WG, no special requirements.

 

[1] https://datatracker.ietf.org/doc/draft-cheng-spring-srv6-encoding-network-sliceid/

 

Best Regards,

Liyan Gong

 


----邮件原文----
 发件人:Lizhenbin  <lizhenbin@huawei.com>
 收件人:"draft-ali-teas-spring-ns-building-blocks@ietf.org" <draft-ali-teas-spring-ns-building-blocks@ietf.org>,"draft-filsfils-spring-srv6-stateless-slice-id@ietf.org" <draft-filsfils-spring-srv6-stateless-slice-id@ietf.org>,"draft-decraene-mpls-slid-encoded-entropy-label-id@ietf.org" <draft-decraene-mpls-slid-encoded-entropy-label-id@ietf.org>
 抄 送: "Dongjie \\(Jimmy\\)" <jie.dong@huawei.com>,"spring@ietf.org" <spring@ietf.org>,"mpls@ietf.org" <mpls@ietf.org>,TEAS WG  <teas@ietf.org>,John E Drake  <jdrake=40juniper.net@dmarc.ietf.org>,"EXT-vishnupavan@gmail.com" <vishnupavan@gmail.com>,Adrian Farrel  <adrian@olddog.co.uk>,Tarek Saad  <tsaad.net@gmail.com>
 发送时间:2021-08-17 00:04:32
 主题:Re: [Teas] New term for the underlay construct used for slicerealization
 
    


Hi authors of draft-ali-teas-spring-ns-building-blocks/draft-filsfils-spring-srv6-stateless-slice-id/draft-decraene-mpls-slid-encoded-entropy-label-id,


 


It is known that your drafts are also related with the underlay construct used for slice realization. It also seems that you use the term with “slice”  for the underlay construct. In the discussion of TEAS WG, there is some consensus to define a neutral new term without “slice”.  Wish to learn your opinions on the new term definition and there would be a convergence on the new term after your participating  in the discussion.


 


 


Best Regards,


Robin


 


 


 



From: Teas [mailto:teas-bounces@ietf.org] On Behalf Of John E Drake
 Sent: Monday, August 16, 2021 8:53 PM
 To: Dongjie (Jimmy) <jie.dong@huawei.com>; EXT-vishnupavan@gmail.com <vishnupavan@gmail.com>; Adrian Farrel <adrian@olddog.co.uk>
 Cc: Tarek Saad <tsaad.net@gmail.com>; TEAS WG <teas@ietf.org>
 Subject: Re: [Teas] New term for the underlay construct used for slice realization




 


Hi,


 


It sounds like slice aggregates, or more generally overlay network service aggregates, are the things which use resource partitions.


 


Yours Irrespectively,


 


John



 


 


Juniper Business Use Only



From: Teas <teas-bounces@ietf.org> On Behalf Of Dongjie (Jimmy)
 Sent: Friday, August 13, 2021 9:20 AM
 To: EXT-vishnupavan@gmail.com <vishnupavan@gmail.com>; Adrian Farrel <adrian@olddog.co.uk>
 Cc: Tarek Saad <tsaad.net@gmail.com>; TEAS WG <teas@ietf.org>
 Subject: Re: [Teas] New term for the underlay construct used for slice realization




 


[External Email. Be cautious of content]


 


Hi Pavan, 


 


Sorry for chiming in, please see some comments inline:


 



From: Teas [mailto:teas-bounces@ietf.org] On Behalf Of Vishnu Pavan Beeram
 Sent: Friday, August 13, 2021 1:32 AM
 To: Adrian Farrel <adrian@olddog.co.uk>
 Cc: Tarek Saad <tsaad.net@gmail.com>; TEAS WG <teas@ietf.org>
 Subject: Re: [Teas] New term for the underlay construct used for slice realization




 


** As a WG participant. **




 Adrian, Hi!




 Thanks for your earlier emails in this thread that have helped drill down the discussion to the specific item that needs a fresh term!
 Please see inline (prefixed VPB).




 -Pavan (as a WG participant)



 


On Thu, Aug 12, 2021 at 10:05 AM Adrian Farrel <adrian@olddog.co.uk> wrote:



Thanks for your useful opinion, Tarek.


 


I have no objection to the use of the word “aggregate”. It is generally used to express grouping together to treat as a single entity or to be treated in the same way.


 


But I do like “foo aggregate” to mean that a number of foo have been aggregated.




 


[VPB] But, that isn’t necessarily how IETF has been using the term “aggregate”.  “Behavior Aggregate” (as defined in IETF) doesn’t mean aggregating behaviors. The same goes for “Treatment Aggregate”. Behavior Aggregate (the way we read/interpret it) is an aggregate with a specific behavior. 


 


[Jie] I just checked the definition of the “aggregate” related terms in the RFCs:


 


Behavior Aggregate (defined in RFC 2474): a collection of packets with the same codepoint crossing a  link in a particular direction.”


 


Traffic Aggregate (defined in RFC 3086): a collection of packets with a codepoint that maps to the same  PHB, usually in a DS domain or some subset of a DS domain.


 


Treatment Aggregate (defined in RFC 5127): This term is defined as the aggregate of Diffserv service  classes.  A treatment aggregate is concerned only with the forwarding treatment of the aggregated traffic,  which may be marked with multiple DSCPs.


 


My reading of these definitions is that “aggregate” here means either aggregated packets or aggregated service classes which are treated in the same  way on a particular node or link.


 


While what we want to describe with the new term IMO is “a group of network resources allocated on a set of network nodes and links”. Such group  of resources can be provisioned in different places of the network and are organized together to provide a specific network-level behavior. 


 


Thus the key information to be delivered with the new term is “a group of organized resources in the network”, rather than “aggregated behavior at  a particular point”.


 


Best regards,


Jie



 


So “slice aggregate” would be an aggregation of slices. Your use in I-D.draft-bestbar-teas-ns-packet is, therefore, confusing. If the slices are *not* separated out into different flows (or traffic streams) then, yes, you are aggregating slices. But if the slices are separated out, as you describe,  then what you have is “IETF network slice traffic stream aggregation”.




 


 


[VPB] Yes. The definition of the slice aggregate (as defined in draft-bestbar-teas-ns-packet) does state that the slice aggregate comprises of one or more IETF network slice traffic streams.  We could have chosen a longer  descriptive name, but opted to keep it short.



 


 


“Network resource aggregate” would imply that resources have been collected together to be used as a single entity.




 


[VPB] Not necessarily. "Network Resource Aggregate" isn't meant to imply "aggregating network resources". The intent behind the proposal is to say that it is an aggregate that has specific network resources. 



 


You might do that, for example, with a set of parallel links that can be aggregated (or bundled) and treated as a single link.


 


I don’t think we are aggregating resources in this case. We are grouping, profiling, partitioning, collecting, or even filtering.


 


Adrian


 



From: Tarek Saad <tsaad.net@gmail.com> 
 Sent: 12 August 2021 15:41
 To: adrian@olddog.co.uk; 'Kiran Makhijani' <kiran.ietf@gmail.com>; 'John E Drake' <jdrake=40juniper.net@dmarc.ietf.org>;  'Dongjie (Jimmy)' <jie.dong@huawei.com>; 'Lizhenbin' <lizhenbin@huawei.com>; teas@ietf.org
 Subject: Re: [Teas] New term for the underlay construct used for slice realization




 


Hi Adrian/all,


 


As described in I-D.ietf-teas-ietf-network-slice-definition, an IETF Network Slice service may include multiple connections that associate sets of endpoints -  each having a set of SLOs/SLEs.


In I-D.draft-bestbar-teas-ns-packet, we defined a Slice Aggregate as a construct that comprises of one or more IETF network slice traffic streams that share the  same set of SLOs/SLEs.


The Slice Aggregate construct allows aggregating streams from multiple IETF Network Slice connections that share common SLOs/SLEs so that the provider network  can offer the same aggregate treatment to them. The Slice Aggregate resources are instantiated on specific network elements as dictated by the Slice Aggregate topology.


 


Since the scope of I-D.draft-bestbar-teas-ns-packet was the realization of IETF Network Slice service in a provider network, we had constrained the aggregate  construct to slices.


 


We understand that the aggregate construct can be generalized to support other services. Let us offer another option to consider for representing the generic  construct: “Network Resource Aggregate”. There are multiple IETF documents that use the term Aggregate whenever grouping multiple service classes (Behavior Aggregate, Treatment Aggregate, Traffic Aggregate,  etc.) - refer to rfc5127 and rfc2474 for more examples.


 


Regards,


Tarek


 


 



From: Teas <teas-bounces@ietf.org> on behalf of Adrian  Farrel <adrian@olddog.co.uk>
 Date: Wednesday, August 11, 2021 at 3:38 PM
 To: 'Kiran Makhijani' <kiran.ietf@gmail.com>, 'John E Drake' <jdrake=40juniper.net@dmarc.ietf.org>,  'Dongjie (Jimmy)' <jie.dong@huawei.com>, 'Lizhenbin' <lizhenbin@huawei.com>, teas@ietf.org <teas@ietf.org>
 Subject: Re: [Teas] New term for the underlay construct used for slice realization



I wonder whether we can pick this apart and put it back together in a way
 that makes sense.
 
 The customer's view of all this is an "IETF network slice service". I think
 (hope) we are all agreed on this. The customer may ask (in shorthand) for a
 "network slice", but:
 - they are talking about IETF technology, so they asking for an "IETF
 network slice"
 - they actually want behavioural characteristics and have no right to tell
 the operator
   how to manage the network, so they are asking for an "IETF network slice
 service."
 
 The operator has a bigger set of things to worry about. 
 
 1. At the top of the operator's view is the "IETF network slice service" as
     requested by the customer. We have this defined already, so nothing more
     to say.
 
 2. The operator maps the request for a slice service into the "IETF network
     slice" which is the expression of the service in terms of network
 connectivity
     in the context of the operator's network. The relationship here is like
 the
     relationship between the L3SM and L3NM.
 
 3. At the bottom of their view is an underlying network. The technology of
 this
    network depends, of course, on the operator's offering, but this is the
 network
    technology being sliced. It may be an IP network, and MPLS network, an
 OTN,
    or whatever. I would call this the "Underlay Network." This network may,
 in
    turn, be built upon an underlay network of the same or a different
 technology,
    and it may be facilitated through network slicing - but this need not
 concern
    us here. 
 
 4. That leaves the glue in the middle: the bit that enables the scaling and
 maps
    the network slice to the network. And I think it is this bit that is
 causing the
    most debate about terminology. There are some points to consider:
 
    a. The term "network resources" applies to the bandwidth, queues,
 buffers,
        etc. available on the links and nodes in the network. That may be 
        extended to refer to whole links and nodes.
 
    b. The number of IETF network slice services is potentially large and the
        operator needs a mechanism to scale the mapping of services to 
        network resources.
 
    c. The IETF network slices may be grouped for identical treatment to
        achieve scaling, where the grouping collects IETF network slices with
        similar SLAs.
 
    d. It may be that different traffic flows within a single IETF network
 slice
         have different characteristics. In this case, it may be beneficial
 to group
         together some of the traffic flows from different slices.
 
    e. The grouped slices/flows are enabled in the network using network
         resources assigned for that purpose. The assignment may be anything
         from a fully-fledged virtual network (such as in ACTN or VPN+),
 through
         network reserved resources (such as in MPLS-TE), and centrally
         accounted resources (such as SDN or possible SR), to statistically
         shared resources.
 
 There seems to be various points for and against 4d. But, it would appear
 that this is an implementation or deployment issue that doesn't change what
 the protocols need to do. So we should probably allow it architecturally, or
 at least, not disallow it.
 
 Of course, as Kiran points out, 4c/d/e may be a pass-through. That is, it is
 not necessary to implement such groupings either because there are only a
 few slices (which has been the view of some operators) or because the
 network systems can handle the number of slices. And it is in the nature of
 architectures of this sort that all functions can be nulled out without loss
 of generality, and we have to recall that the internals of provisioning
 systems may appear as functional blocks in our architectures, but we don't
 compel implementations to adhere to that type of architecture. So I don't
 think we have to worry on that account.
 
 And that brings the question of how we name the resources that are gathered
 in 4e. 
 
 I can't decide whether it is helpful to spend time saying why I don't like
 each of the proposed terms. I certainly have things I don't like about (for
 example) "slice aggregate" (because of 4d, which means it is really a "slice
 sub-flow aggregate"), and I am not a fan of "VTN" (because of "transport"
 and maybe it is not really a network). But maybe it is better for me to say
 what I think we should call things? I think we have...
 
 -       IETF network slice service (customer view)
 -       IETF network slice (operator view)
 -       Resource partition (delivery mechanism)
 -       Underlay network (network used to support the slice)
 
 Why "resource partition"? Well it is a collection of "nodes, links, and
 network resources that are marked within the network for use by a set of
 network slice traffic flows".
 It is possible that the word "partition" is too strong because it may imply
 to some people that resources in a partition cannot be shared, but I don't
 feel that.
 Softer words than "partition" would be "group", "bundle", "pool", and I
 could live with any of them.
 
 Best,
 Adrian
 
 
 -----Original Message-----
 From: Teas <teas-bounces@ietf.org> On Behalf Of Kiran Makhijani
 Sent: 11 August 2021 16:00
 To: John E Drake <jdrake=40juniper.net@dmarc.ietf.org>; Dongjie (Jimmy)
 <jie.dong@huawei.com>; Lizhenbin <lizhenbin@huawei.com>; teas@ietf.org
 Subject: Re: [Teas] New term for the underlay construct used for slice
 realization
 
 Hi John, (and all),
 
 Two very basic clarification questions:
 1. How do we differentiate between  the slice-segments that are 
 resource-aware vs those that are not? I had assumed that since a slice 
 has an SLO, it will need network resource allocations in some form.
 
 2. Is it ok to assume that the customer view of slice is an 'IETF 
 network slice service' and the 'IETF slice realization' of that service 
 in a provider network is raises the question of underlay and overlay 
 constructs. Am I right?
 (a) if so, then we are acknowledging  the presence of another layer of 
 abstraction (for realization). It could be underlay/overlay or 
 aggregate/??. Then the term 'slice aggregate' is better and my 
 preference, it is easier to see that different slice-services are 
 aggregated into a single construct  in a provider network. Use of 
 underlay/overlay are confusing.
 (b) for a leaner provisioning, I would also prefer to see it documented 
 that the aggregate is optional and it should be possible to directly map 
 a slice-service to physical or real resources in the network. 
 specifically useful when a single domain is carving out slices for 
 different purposes.
 
 Thanks
 Kiran
 
 
 ------ Original Message ------
 From: "John E Drake" <jdrake=40juniper.net@dmarc.ietf.org>
 To: "Dongjie (Jimmy)" <jie.dong@huawei.com>; "Lizhenbin" 
 <lizhenbin@huawei.com>; "teas@ietf.org" <teas@ietf.org>
 Sent: 8/11/2021 5:38:05 AM
 Subject: Re: [Teas] New term for the underlay construct used for slice 
 realization
 
 >Jimmy,
 >
 >Snipped, comments inline.
 >
 >Yours Irrespectively,
 >
 >John
 >
 >
 >Juniper Business Use Only
 >
 >>  -----Original Message-----
 >>  From: Dongjie (Jimmy) <jie.dong@huawei.com>
 >>  Sent: Tuesday, August 10, 2021 11:03 PM
 >>  To: John E Drake <jdrake@juniper.net>; Lizhenbin <lizhenbin@huawei.com>;
 >>teas@ietf.org
 >>  Subject: RE: New term for the underlay construct used for slice
 realization
 >>
 >>  [External Email. Be cautious of content]
 >>
 >underlay construct for network slice realization bound to
 >>  > > network slice services? That is, is the underlay construct only for
 >>  > > use in network slicing, or should it be generalized for more
 possible uses?
 >>  >
 >>  > [JD] Absolutely yes
 >>
 >>  [Jie] I guess you mean "Yes" to the latter case, which is "it should be
 generalized
 >>  for more possible uses", is my understanding correct?
 >
 >[JD]  Yes to the latter
 >
 >>
 >>  >
 >>  > >
 >>  > > 2.      If the answer to question 1 is YES, should it reflect the
 following
 >>  > > characteristics?
 >>  > >
 >>  > > a.      It is about the underlay
 >>  > > b.      It is about the partitioned resources used to deliver the
 network slice
 >>  > > services
 >>  > > c.      It allows the 1:1, N:1, and 1:N mapping models between the
 network
 >>  > slice
 >>  > > services and the underlay construct. The 1:1 and N:1 mapping may be
 >>  > > straightforward. Does it also make sense to divide the elements or
 >>  > > traffic flows in a single network slice service to carry them in
 >>  > > different
 >>  > underlay constructs?
 >>  >
 >>  > [JD]  Yes to all of the above.  Please see:
 >>  > https://urldefense.com/v3/__https://datatracker.ietf.org/doc/html/draf
 >>  > t-drake-bess-enhanced-vpn-06__;!!NEt6yMaO-
 >>  gk!TCiJHCZCwFgwpuFoujxVlZ4r9
 >>  > F6mLpE4nJ-9zpqkY-kls-ROxL4C2_xNaR2ImI4$
 >>  > >
 >>  > > Lastly, here are some candidates of the "new term":
 >>  > >
 >>  > > Option 1: The network slice service is called "overlay slice", then
 >>  > > the underlay construct is called "underlay slice".
 >>  > >
 >>  > > Option 2: The network slice service is called "service slice", then
 >>  > > the underlay construct is called "resource slice".
 >>  >
 >>  > [JD]  I don't think we need another term for what we are already
 >>  > calling an 'IETF Network Slice Service'.  Adrian and I are considering
 >>  > the term 'resource partition' to describe the partitioning of underlay
 >>  > network resources in support of various overlay services such as IETF
 Network
 >>  Slice Services.
 >>  > This is congruent with the ideas expressed in:
 >>  > https://urldefense.com/v3/__https://datatracker.ietf.org/doc/html/draf
 >>  > t-ietf-spring-resource-aware-segmen__;!!NEt6yMaO-
 >>  gk!TCiJHCZCwFgwpuFouj
 >>  > xVlZ4r9F6mLpE4nJ-9zpqkY-kls-ROxL4C2_xNxEfwaXg$
 >>  > ts-03.  What this allows one to build is an 'partitioned underlay
 >>  > network topology'.
 >>
 >>  [Jie] Agree that here we are talking about the term for the underlay
 construct.
 >>  "Resource partition" captures one of its key characteristics, while IMO
 another
 >>  thing the term needs to reflect is that the resource partition is needed
 on a
 >>  subset of the links and nodes (rather than on a single node or link) in
 the physical
 >>  network, which together builds a logical network topology.
 >
 >[JD]  In my initial email, above, I was proposing 'partitioned underlay
 network topology'
 >
 >>
 >>  Best regards,
 >>  Jie
 >>
 >>  >
 >>  > >
 >>  > > Your opinion about these candidates are much appreciated. You may
 >>  > > also propose other new term if it complies with the above two
 points.
 >>  >
 >>  > [JD]  I think you have exceeded your remit.
 >>  >
 >>  > >
 >>  > >
 >>  > >
 >>  > > Best Regards,
 >>  > > Robin
 >>  > >
 >>  > > _______________________________________________
 >>  > > Teas mailing list
 >>  > > Teas@ietf.org
 >>  > > https://urldefense.com/v3/__https://www.ietf.org/mailman/listinfo/te
 >>  > > as
 >>  > > __;!!N
 >>  > > Et6yMaO-gk!Q0ycOf0ELxT6mG1GbnO4LSL-Q99J4uu7jfdUtBECaI-
 >>  > > O08HqD31TGJciNjuxL2A$
 >>  >
 >>  > _______________________________________________
 >>  > Teas mailing list
 >>  > Teas@ietf.org
 >>  > https://urldefense.com/v3/__https://www.ietf.org/mailman/listinfo/teas
 >>  > __;!!NEt6yMaO-gk!TCiJHCZCwFgwpuFoujxVlZ4r9F6mLpE4nJ-9zpqkY-kls-
 >>  ROxL4C2
 >>  > _xNDCrPaNQ$
 >
 >_______________________________________________
 >Teas mailing list
 >Teas@ietf.org
 >https://www.ietf.org/mailman/listinfo/teas
 
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