Subject: [Teas-ns-dt] Isolation

From: John E Drake <[email-masked]>
Date: Mon, 10 Feb 2020 15:14:32 +0000

My list currently consists of:

Protection isolation - a failure in the network will not impact a customer's service for longer than X seconds, where X is a number in the range 50 msecs to some number of seconds, as specified in the SLO

Reachability isolation - a customer's packets will not be misdelivered to another customer with a probability of X, where X is a percentage in the range 100 to some lower percentage, as specified in the SLO

Performance isolation - a customer's performance related SLO parameters will not be degraded by more than X, where X is a percentage in the range of 0 to some higher percentage, as specified in the SLO

Yours Irrespectively,

John

Juniper Business Use Only

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From: Greg Mirsky <[email-masked]>
Date: Mon, 10 Feb 2020 19:09:38 -0800

Hi John,
thank you for starting the discussion. Please find my notes in-line below
under GIM>> tag.

Regards,
Greg

On Mon, Feb 10, 2020 at 8:19 AM John E Drake <jdrake=
[email-masked]> wrote:

> Protection isolation - a failure in the network will not impact a
> customer's service for longer than X seconds, where X is a number in the
> range 50 msecs to some number of seconds, as specified in the SLO
>
GIM>> If we envision that a transport network slicing may provide an
underlay for applications like TSN and/or DetNet, then the lower boundary
must be lowered even further. In fact, 50 msec switchover and 10 msec
failure detection are, AFAIK, historical numbers that, I'd expect, should
be revisited as an impact on service now is more significant than it was at
the time of DS1/T1.

>
> Reachability isolation - a customer's packets will not be misdelivered to
> another customer with a probability of X, where X is a percentage in the
> range 100 to some lower percentage, as specified in the SLO
>
GIM>> I think that this is about connectivity guarantee or, its opposite,
misconnection (rate or level?).

>
> Performance isolation - a customer's performance related SLO parameters
> will not be degraded by more than X, where X is a percentage in the range
> of 0 to some higher percentage, as specified in the SLO
>
GIM>> We probably need to further characterize how the degradation being
measured, i.e., measurement interval, measurement frequency.

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> Teas-ns-dt mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/teas-ns-dt
>

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From: Stewart Bryant <[email-masked]>
Date: Tue, 11 Feb 2020 07:17:14 +0100

Sent from my iPad

> On 10 Feb 2020, at 17:19, John E Drake <jdrake=[email-masked]> wrote:
> 

Performance isolation can be quite subtle.

An effect that was found in the testing of high quality time distribution concerned the beating of two almost in sync sources. What happened was that A led B, with B going slightly faster than A. The when B overtook A, A suffered a phase hit.

It is also worth looking at the Detnet Security Framework where we have been trying to understand the dynamics.

Stewart