Re: [Teas-ns-dt] Appendix text on isolation

[Jari Arkko <[e-mail]>]

Here’s a suggested 2nd revision of the suggested text, based on yesterday’s comments on the call and Kiran’s email.


Transport slices are perceived as if slice was provisioned for the
customer as a dedicated network with specific SLOs. These committed
SLOs for a given customer should be maintained during the life-time of
the slice even in the face of potential disruptions.  Such disruptions
include sudden traffic volume changes either from the customer itself
or others, equipment failures in the service provider network, and
various misbehaviors or attacks.

The service provider needs to ensure that their network can provide
the requested slices with the availability agreed with its
customers. Some of the main technical approaches to
ensuring guarantees are about network planning, managing capacity,
priority mechanisms, policing or shaping customer traffic, selecting
dedicated resources, and so on.
One term that has commonly been also used in this context is
"isolation". This is discussed further in the framework draft
[I-D.nsdt-teas-ns-framework] and has also been a topic in
[I-D.ietf-teas-enhanced-vpn].
The term “isolation” implies in part traffic separation (a common
feature in VPNs) and in part the selection of dedicated
resources. Dedicated resources can help assure that, for instance,
traffic in other slices does not affect a given slice. However, it
should also be noted that this is one particular realization of a
requirement for guarantees, and other mechanisms may also be used,
such as priority mechanisms or policing amount of traffic entering a
link from different sources.
It should also be noted that neither dedicated resources or the other
mechanisms can provide a 100% guarantee against problems.  To maintain
protection against resource and equipment failures techniques such as
redundancy are needed.