Re: [Teas] [Netslices] terminology discussion network slicing

[Daniele Ceccarelli <[e-mail]>]

Hi Sebastian,

this definition IMHO is so generalized that is always correct but at the same time too vague that is prone to different interpretations.

We all started from this definition and came out with so many different points of view. According to this definition a network slice can be almost everything.

BR
Daniele

From: sebastian [mailto:[e-mail]]
Sent: sabato 27 maggio 2017 21:13
To: 'Greg Mirsky' <[e-mail]>
Cc: 'Leeyoung' <[e-mail]>; [e-mail]; [e-mail]; Daniele Ceccarelli <[e-mail]>
Subject: RE: [Netslices] [Teas] terminology discussion network slicing

Hello, Greg,

Concur with the following generalized definition of a network slice:

"A set of network functions and the resources for these network functions which are arranged and configured, forming a complete logical network to meet certain network characteristics."

The existence certain artifacts, such as tunnels or other attributes that in unison provide some capability, does not alter the notion that it is still some arrangement of resources (e.g. functions, storage, spectrum etc.)

The scope of a network slice must also be extensible to any set of endpoints (e.g. orchestration across multiple administrative domains).

Many thanks.
-Sebastian

From: Netslices [mailto:[e-mail]] On Behalf Of Greg Mirsky
Sent: Wednesday, May 24, 2017 7:49 AM
To: Daniele Ceccarelli <[e-mail]<mailto:[e-mail]>>
Cc: Leeyoung <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>
Subject: Re: [Netslices] [Teas] terminology discussion network slicing

Hi Daniele,
thank you for your kind and thorough consideration, glad we agree on the terminology. One minor, I think, note and the answer to your question under GIM2>> tag in-line.

Regards,
Greg

On Wed, May 24, 2017 at 4:39 AM, Daniele Ceccarelli <[e-mail]<mailto:[e-mail]>> wrote:
Hi Greg,

good points. Please see in line.

Cheers
Daniele

From: Greg Mirsky [mailto:[e-mail]<mailto:[e-mail]>]
Sent: sabato 20 maggio 2017 06:14
To: Daniele Ceccarelli <[e-mail]<mailto:[e-mail]>>
Cc: Leeyoung <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>
Subject: Re: [Netslices] [Teas] terminology discussion network slicing

Hi Daniele,
I think that my interpretation of network slice construct definition by 3GPP is slightly different. Please find my comments in-line tagged GIM>>. Some are to do with terminology but, I believe, it is helpful to settle the dictionary and agree on the interpretation of terms.

Regards,
Greg

On Sat, May 20, 2017 at 4:18 AM, Daniele Ceccarelli <[e-mail]<mailto:[e-mail]>> wrote:
Hi Young, all,

i agree with your conclusion but would like to clarify one thing that IMO got lost in the discussion since its beginning.

The 3GPP definition says:
"A set of network functions and the resources for these network functions which are arranged and configured, forming a complete logical network to meet certain network characteristics."

This means that a network slice IS NOT a VPN or a TE Tunnel.
GIM>> My view is that VPN or a TE Tunnel could be part of instantiation of a network slice. There likely to be additional to TE parameters that may be considered, depending on the profile of the service requested the NS.
[>DC] I should have said “this means that a network might not be JUST a VPN or a TE Tunnel” and hence agree with you on the fact that the VPN or the TE Tunnel could be part of the network slice.

A network slice is "something" (netslices and 3GPP will define what this something is) that is composed by a "piece" in the RADIO domain, a "piece" in the CLOUD domain, a "piece" in the TRANSPORT domain, plus possible other pieces in possible other domains.
GIM>> I see separation of RAN and "transport" networks. Indeed, there will be e2e construct (will it be still referred as "network slice" or "multi-domain NS") but it can be decomposed into domain-scope NSes. What you referred to as "piece" I consider as domain-scope NS.
[>DC] This is another terminology issue. I agree on the separation between the RAN domain and the “transport” domain (let’s keep on using the work transport with quotation marks for the time being) and all the other domains in the network. IMO the network slice is the end to end entity that is built by a RAN slice plus a “transport” slice plus other potential slices. And the “transport” slice could be a VPN, a TE tunnel…
GIM2>> If to a segment of a network slice instance in a core network we refer as transport domain, then, as I understand, it's peer may be not only RAN segment but, e.g., segment of an access network of another kind.

The word "transport" can be misleading here since one could think of transport technologies (e.g. WDM, OTN), but what I'm referring to as TRANSPORT DOMAIN is that part of the network that is used to carry a packet between two other domains.
In order to have a slice, that portion of the transport domain needs to be engineered, hence it is all about building a TE entity and stitching services to such entity. This is what is in the ACTN scope.
GIM>> Should we use Client-Server terms?
[>DC] WRT what? Do you mean wrt the fact that the relationship between e.g. the RAN slice and the “transport” slice could be client- server? I see it more a peering relationship. ON the other side WITHIN the “transport” slice you could have different layers with client-server relationship, that’s right.
GIM2>> Yes, should have been clearer, it is the latter.

My very personal opinion is that whatever belongs to the transport domain belongs to IETF (and is already being addressed), while the rest is a dangerous duplication of concepts standardized is other SDOs...but this is another discussion that doesn't fit here.

BR
Daniele


-----Original Message-----
From: Teas [mailto:[e-mail]<mailto:[e-mail]>] On Behalf Of Leeyoung
Sent: venerdì 19 maggio 2017 15:15
To: [e-mail]<mailto:[e-mail]>
Cc: [e-mail]<mailto:[e-mail]>
Subject: Re: [Teas] terminology discussion network slicing

Hi,

Lou is right. There is a dedicated email list for the discussion of "network slicing (cc'ed)" and the discussion about what that term means should be held on that list.

We have used similar language in draft-ietf-teas-actn-framework right from the
00 version. Recent changes have been an attempt to clarify what the terminology means in the context of ACTN. We are not trying to define or redefine "network slicing" in the ACTN document, but are trying to make it clear how ACTN works.

Therefore I propose the following resolution:

1. All discussion of the general applicability and definition of "network slicing" is held on the netslices mailing list.

2. We adopt Adrian's suggestion to explain that the scope of the definition of the terms used in the ACTN framework is limited to ACTN. That means effectively that if there are components of a wider definition of network slicing that are not supported by ACTN, that will be OK.

I propose to post an updated version in the next few days and I believe that will allow this draft to move ahead without being blocked by the discussion in netslices. Once the IETF has a stable definition of network slicing we can return and see how ACTN is applicable to that definition an whether more wok is need (in a separate draft).

Thanks,
Young

-----Original Message-----
From: Lou Berger [mailto:[e-mail]<mailto:[e-mail]>]
Sent: Tuesday, May 16, 2017 8:35 AM
To: Igor Bryskin <[e-mail]<mailto:[e-mail]>>; Belotti, Sergio (Nokia - IT/Vimercate) <[e-mail]<mailto:[e-mail]>>; Gert Grammel <[e-mail]<mailto:[e-mail]>>; Leeyoung <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>
Subject: Re: [Teas] terminology discussion network slicing

Perhaps it's time to bring the discussion to the slicing list and report back their reaponse....

Lou


On May 16, 2017 8:31:19 AM Igor Bryskin <[e-mail]<mailto:[e-mail]>> wrote:

> Hi Sergio,
>
> I would also like to hear more from network slicing experts.
>
> My understanding is that the difference in the separation (in terms of
> control and data planes, security, etc.). For example, traditional BGP
> based L3 VPNs (that use provider's common control plane for their
> management and IP/MPLS TE tunnels to inter-connect their PEs) will
> probably not be able guarantee for the clients msec range connectivity
> setup times required by 5g, while provided by the same provider fully
> separated/genuinely private IP/MPLS networks (that do not share
> IP/MPLS control plane and infrastructure, whose network topology is
> supported by separate L0/L1 connections) hopefully will be able to
> provide such guarantees. Therefore, I define layer network slices as
> dynamically managed fully isolated in control and data planes private
> TE layer networks, which may share one or more underlying server layer networks.
>
>
> Cheers,
> Igor
>
>
>
>
> -----Original Message-----
> From: Teas [mailto:[e-mail]<mailto:[e-mail]>] On Behalf Of Belotti, Sergio
> (Nokia - IT/Vimercate)
> Sent: Tuesday, May 16, 2017 6:08 AM
> To: Gert Grammel; Leeyoung; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>
> Subject: Re: [Teas] terminology discussion network slicing
>
> Hi Gert,
>
> "Thinking a bit about it I came to the point where "VPN" and "network
> slices" seem to describe the same entity or at least a "network slice"
> being a VPN of VPNs?"
>
> I share completely your conclusion , I'd like if someone can explain
> if a difference really exists .
>
> Thanks
> Sergio
>
>
> -----Original Message-----
> From: Teas [mailto:[e-mail]<mailto:[e-mail]>] On Behalf Of Gert Grammel
> Sent: Monday, May 15, 2017 7:02 PM
> To: Leeyoung <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>
> Subject: Re: [Teas] terminology discussion network slicing
>
> Leeyoung,
>
> Thank you for taking a stab on this. Usually when getting to a
> definition, I try to establish what kind of existing constructs would
> fall under the definition. If my understanding is correct, the
> following list of constructs would all satisfy the definition somehow.
> - A TDM network with a p2p TDM connection
> - A PSC capable network carrying a p2p circuit (such as EPL/EVPL)
> - An MPLS LSP using a traffic engineered IP network
> - A L2VPN using a traffic engineered MPLS network
> - A L3VPN using a traffic engineered IP network
> - A TCP connection using a traffic engineered IP network
> - Different QoS classes in an IP network
>
> Thinking a bit about it I came to the point where "VPN" and "network
> slices" seem to describe the same entity or at least a "network slice"
> being a VPN of VPNs?
>
> Gert
>
>
> On 2017-05-17, 16:44, "Teas on behalf of Leeyoung"
> <[e-mail]<mailto:[e-mail]> on behalf of [e-mail]<mailto:[e-mail]>> wrote:
>
>     Hi Adrian and others,
>
>     We'd like cross check with you on some terminology we introduced newly. Any
>     comment on these terms will be greatly appreciated.
>
>     We introduced 'network slicing' as follows:
>
>             Network slicing is a collection of resources
>             that are used to establish logically dedicated virtual networks
>             over TE networks. It allows a network provider to provide
>             dedicated virtual networks for application/customer over a
>             common network infrastructure. The logically dedicated
>             resources are a part of the larger common network
>             infrastructures that are shared among various network slice
>             instances which are the end-to-end realization of network
>             slicing, consisting of the combination of physically or
>             logically dedicated resources.
>
>
>     Thanks.
>     Young and Daniele
>     -----Original Message-----
>     From: Leeyoung
>     Sent: Friday, May 05, 2017 1:41 PM
>     To: [e-mail]<mailto:[e-mail]>
>     Subject: RE: [Teas] I-D Action:
> draft-ietf-teas-actn-framework-05.txt
>
>     Hi,
>
>     This update is intended to incorporate the comments from the last WG
>     meeting and any pending issues. We also have taken the global editorial
>     changes to make it consistent through the document. Major changes are:
>
>     - Inclusion of "network slicing" definition from ACTN perspective (in the
>     terminology section)
>     - Added virtual network service (VNS) section (Section 3) to define types
>     of VNS.
>     - Incorporated "orchestration" (service/network) mapping to ACTN
>     architecture (See Section 5.2)
>     - Created a new section 6 (Topology Abstraction Method) where we imported
>     some texts from ACTN abstraction method
>     https://tools.ietf.org/html/draft-lee-teas-actn-abstraction-01
>     - Added Appendices A & B to discuss example deployment scenarios such as
>     example of MDSC and PNC functions integrated in Service/Network
>     Orchestrator (Appendix A) and example of IP + Optical network with L3VPN
>     service (Appendix B)
>
>     In regard to ACTN abstraction method draft, we are going to keep it as a
>     separate draft and use this document to elaborate other aspects not
>     imported to the framework document.
>
>     The following diff pointer will help you see the changes with this revision:
>
> https://www.ietf.org/rfcdiff?url2=draft-ietf-teas-actn-framework-05
>
>     The co-authors believe that the document is ready for WG LC. Any
>     changes/comments will be appreciated.
>
>     Thanks & Best regards,
>     Young & Daniele (on behalf of other co-authors/contributors)
>
>     -----Original Message-----
>     From: Teas [mailto:[e-mail]<mailto:[e-mail]>] On Behalf Of [e-mail]<mailto:[e-mail]>
>     Sent: Friday, May 05, 2017 10:41 AM
>     To: [e-mail]<mailto:[e-mail]>
>     Cc: [e-mail]<mailto:[e-mail]>
>     Subject: [Teas] I-D Action: draft-ietf-teas-actn-framework-05.txt
>
>
>     A New Internet-Draft is available from the on-line Internet-Drafts directories.
>     This draft is a work item of the Traffic Engineering Architecture and
>     Signaling of the IETF.
>
>             Title           : Framework for Abstraction and Control of Traffic
>             Engineered Networks
>             Authors         : Daniele Ceccarelli
>                               Young Lee
>       Filename        : draft-ietf-teas-actn-framework-05.txt
>       Pages           : 41
>       Date            : 2017-05-05
>
>     Abstract:
>        Traffic Engineered networks have a variety of mechanisms to
>        facilitate the separation of the data plane and control plane. They
>        also have a range of management and provisioning protocols to
>        configure and activate network resources.  These mechanisms
>        represent key technologies for enabling flexible and dynamic
>        networking.
>
>        Abstraction of network resources is a technique that can be applied
>        to a single network domain or across multiple domains to create a
>        single virtualized network that is under the control of a network
>        operator or the customer of the operator that actually owns
>        the network resources.
>
>        This document provides a framework for Abstraction and Control of
>        Traffic Engineered Networks (ACTN).
>
>
>
>     The IETF datatracker status page for this draft is:
>     https://datatracker.ietf.org/doc/draft-ietf-teas-actn-framework/
>
>     There are also htmlized versions available at:
>     https://tools.ietf.org/html/draft-ietf-teas-actn-framework-05
>
> https://datatracker.ietf.org/doc/html/draft-ietf-teas-actn-framework-0
> 5
>
>     A diff from the previous version is available at:
>
> https://www.ietf.org/rfcdiff?url2=draft-ietf-teas-actn-framework-05
>
>
>     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<http://tools.ietf.org>.
>
>     Internet-Drafts are also available by anonymous FTP at:
>     ftp://ftp.ietf.org/internet-drafts/
>
>     _______________________________________________
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