Re: [Teas] Definitions of VTN and Slice Aggregate in the drafts

["Belotti, Sergio (Nokia - IT/Vimercate)" <[e-mail]>]

Hi Jie,
Clarification on terminology is always a good effort to do  thanks for that.
On the other hand I'd like to understand , about "VTN", what is the difference in your VTN concept with respect what already defined in RFC 8453 in section 2.1?
In that section there is a description also of the two types of VN , customer can manage.
A parallel effort with draft-ietf-teas-actn-vn-yang permits to "create" VN of the desired type.
So my question is : what in your "new" VTN is different with respect what already defined related to VN to force using another term ?

Thanks
Sergio





From: Teas <[e-mail]> On Behalf Of Dongjie (Jimmy)
Sent: Tuesday, March 9, 2021 7:38 PM
To: [e-mail]
Subject: [Teas] Definitions of VTN and Slice Aggregate in the drafts

Hi all,

In today's meeting, some people raised comments about the confusions caused by the multiple terms. To help the understanding with the term "VTN" and "Slice Aggregate", I reread the text about their definitions and descriptions in each draft.

Although the terminologies are described in different ways, IMO the essential information behind is the same: a logical network construct consists of the topology attribute and the network resources attributes.

Some effort to resolve the terminology overlap could help to reduce the confusions and provide a consistent view on the framework and technologies for network slice realization.


Here are the text about the terms quoted from each draft:

- VTN (in draft-ietf-teas-enhanced-vpn-07):

VPN+ is built from a VPN overlay and an underlying Virtual Transport Network (VTN) which has a customized network topology and a set of dedicated or shared resources in the underlay network.

A VTN is a virtual underlay network that connects customer edge points. The VTN has the capability to deliver the performance characteristics required by an enhanced VPN customer and to provide isolation between separate VPN+ instances.


- Slice Aggregate (in draft-bestbar-teas-ns-packet-02)

This document introduces the notion of a slice aggregate which comprises of one of more IETF network slice traffic streams. It describes how a slice policy can be used to realize a slice aggregate by instantiating specific control and data plane behaviors on select topological elements in IP/MPLS networks.

When logical networks representing slice aggregates are realized on top of a shared physical network infrastructure, it is important to steer traffic on the specific network resources allocated for the slice aggregate.

Slice aggregate: a collection of packets that match a slice policy selection criteria and are given the same forwarding treatment; a slice aggregate comprises of one or more IETF network slice traffic streams; the mapping of one or more IETF network slices to a slice aggregate is maintained by the IETF Network Slice Controller.


- Slice policy (in draft-bestbar-teas-ns-packet-02, to help the understanding of Slice Aggregate)

Slice policy: a policy construct that enables instantiation of mechanisms in support of IETF network slice specific control and data plane behaviors on select topological elements; the enforcement of a slice policy results in the creation of a slice aggregate.

A slice policy topology may include all or a sub-set of the physical nodes and links of an IP/MPLS network; it may be comprised of dedicated and/or shared network resources (e.g., in terms of processing power, storage, and bandwidth).

Best regards,
Jie