Re: [Teas] New term for the underlay construct used for slice realization

Hi Robin, 

Thanks for the summary of the background and the analysis about the characteristics of the underlay construct for slice realization, please see my comments inline:

> -----Original Message-----
> From: Teas [mailto:teas-bounces@ietf.org] On Behalf Of Lizhenbin
> Sent: Tuesday, August 10, 2021 11:21 PM
> To: teas@ietf.org
> Subject: [Teas] New term for the underlay construct used for slice realization
> 
> Hi Folks,
> 
> On the TEAS meeting in IETF 111, it was discussed that a common "new term"
> will need to be proposed for the underlay construct used for slice realization.
> 
> There have been several related terminologies:
> 
> 1.	VTN (Virtual Transport Network)
> 
> In the early days of network slicing discussion in IETF, it was suggested that the
> technology in IETF should be neutral and not bound to network slicing only.
> Following this approach, the term VTN is defined in the enhanced VPN draft
> already adopted and progressing in TEAS. It is expected that the VTNs with
> guaranteed resources can also be applicable to services other than network
> slices. The VPN+ architecture allows flexible mapping (including 1:1, N:1 and 1:N
> mapping) between the overlay VPN services and the underlay VTNs. Since VTN is
> a generic term, in the context of network slicing we may still need a specialized
> term.
> 
> 2.	Slice Aggregate
> 
> It is claimed that the scope of Slice Aggregate is tied to the scope of IETF
> network slices. This term implies an aggregation of one or more IETF network
> slices into an aggregate construct, so that only a 1:1 and N:1 mapping of
> network slice service to underlay construct can be achieved. However, if this is a
> mapping of network slice traffic streams to underlay constructs, then it may be
> possible to map network slice services to the underlay construct as 1:1, N:1 and
> 1:N, but the name may be confusing because it is not the slices that are
> aggregated.
> 
> With this background in mind, now we can discuss how to define the new term.
> Here are some points for the WG to consider:
> 
> 1.	Should the 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?

[Jie] I'm OK with defining a new term specialized for the context of network slice realization, as we already have a neutral term for generic purpose. 

> 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?

Yes to all. For the 1:N mapping in c, some further analysis about the use cases could be helpful. 

> 
> 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".
> 
> Your opinion about these candidates are much appreciated. You may also
> propose other new term if it complies with the above two points.

[Jie] For slice specific new terms, here are some other candidates: 

Option 3: The network slice service is called "network slice", the underlay construct is called "SUN (Slice Underlay Network)"

Option 4: The network slice service is called "network slice", the underlay construct is called "SRN (Slice Resource Network)"

Option 5: The network slice service is called "network slice", the underlay construct is called "STN (Slice Transport Network or Slice TE Network)"

Best regards,
Jie

> 
> 
> 
> Best Regards,
> Robin
> 
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