[ippm] Availability metrics in the IETF Network Slice

[Greg Mirsky <[e-mail]>]

Hi Adrian, et al,
I've got a question about the relationship of performance metrics like
packet loss ratio, packet delay, packet delay variation of an IETF Network
Slice service (NSS), on one hand, and IETF NSS availability. I think that
Section 4.1.1.1 considers all these metrics as Directly Measurable SLOs. I
agree with such characterization in regard to loss and delay while I am not
sure that that applies to the availability. The issue I have is that, as
far as I know, there's no formal definition of the availability metric in
the document and it seems that we've been using it in a colloquial way. A
group of us started to work on a definition of the availability as a
performance metric for a multi-SLO service
<https://datatracker.ietf.org/doc/draft-mhmcsfh-ippm-pam/>. We had
discussed this work at the IPPM WG meeting at IETF-113. I think that this
work is relevant to the discussion of the IETF NSS availability. If that is
the case, perhaps the characterization of the availability in Section
4.1.1.1 can be further enhanced with the reference to
the draft-mhmcsfh-ippm-pam.
I greatly appreciate your comments, questions, and suggestions on our work
on Precision Availability Metrics.

Regards,
Greg

PS. Attached, please find the presentation slides from the IPPM WG meeting.