Last Call Review of draft-ietf-bmwg-vswitch-opnfv-03
review-ietf-bmwg-vswitch-opnfv-03-genart-lc-romascanu-2017-05-11-00

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Document: draft-ietf-bmwg-vswitch-opnfv-??
Reviewer: Dan Romascanu
Review Date: 2017-05-11
IETF LC End Date: 2017-05-15
IESG Telechat date: Not scheduled for a telechat

Summary:

Almost Ready.

This document describes describes the progress of the Open Platform for NFV
(OPNFV) project on virtual switch performance "VSPERF". That project reuses the
BMWG framework and specifications to benchmark virtual switches implemented in
general-purpose hardware. Some differences with the benchmarking of specialized
HW platforms are identified and they may become work items for BMWG in the
future. It's a well written and clear document, but I have reservations about
it being published as an RFC, and I cannot find coverage for it in the WG
charter. I also have concerns that parts of the methodology used by OPNFV break
the BMWG principles, especially repeatability and 'black-box', and this is not
clear enough articulated in the document.

Major issues:

1. It is not clear to me why this document needs to be published as an RFC. The
introduction says: 'This memo describes the progress of the Open Platform for
NFV (OPNFV) project on virtual switch performance "VSPERF".  This project
intends to build on the current and completed work of the Benchmarking
Methodology Working Group in IETF, by referencing existing literature.' Why
should the WG and the IESG invest resources in publishing this, why an I-D or
an Independent Stream RFC is not sufficient? The WG charter says something
about: 'VNF and Related Infrastructure Benchmarking: Benchmarking Methodologies
have reliably characterized many physical devices. This work item extends and
enhances the methods to virtual network functions (VNF) and their unique
supporting infrastructure. A first deliverable from this activity will be a
document that considers the new benchmarking space to ensure that common issues
are recognized from the start, using background materials from industry and
SDOs (e.g., IETF, ETSI NFV).'. I do not believe that this document covers the
intent of the charter, as it focused on one organization only.

2. In section 3 there 'repeatability' is mentioned, while acknowledging that in
a virtual environment there is no guarantee and actually no way to know what
other applications are being run. Measuring parameters as the ones listed in
3.3 provides just part of the answer, and they are internal parameters to the
SUT. Also, the different deployment scenarios in section 4 require different
configurations for the SUT, thus breaking the 'black-box' principle. I believe
that there is a need for a more clear explanation of why BMWG specifications
are appropriate and how comparison can be made while repeatability cannot be
ensured, and measurements are dependent upon parameters internal to the SUT.

Minor issues:

1. Some of the tests mentioned in Section 4 have no prior or in progress work
in the IETF: Control Path and Datapath Coupling Tests, Noisy Neighbour Tests,
characterization of acceleration technologies. If new work is needed / proposed
to be added for the BMWG scope and framework it would be useful for BMWG to
list these separately.

Nits/editorial comments:

1. What is called 'Deployment scenarios' from VS perspective in Section 4
describe in fact different configurations of the SUT in BMWG terms. It seems
better to separate this second part of section 4 in a separate section. If it
belongs to an existing section it rather belongs in 3 than in 4.