Subject: [Tsv-art] Tsvart last call review of draft-ietf-teas-native-ip-scenarios-08

From: Olivier Bonaventure via Datatracker <[email-masked]>
Date: Fri, 27 Sep 2019 12:56:44 -0700

Reviewer: Olivier Bonaventure
Review result: Not Ready

This document has been reviewed as part of the transport area review team's
ongoing effort to review key IETF documents. These comments were written
primarily for the transport area directors, but are copied to the document's
authors and WG to allow them to address any issues raised and also to the IETF
discussion list for information.

When done at the time of IETF Last Call, the authors should consider this
review as part of the last-call comments they receive. Please always CC
[email-masked] if you reply to or forward this review.

This draft is an unusual draft since it describes simulation results for a
technology that is described in other drafts. From the transport area
viewpoint, I do not see any specific point to report about this draft.

However, as a researcher with some knowledge of traffic engineering techniques,
I'm surprised by the content of the draft. It is unusual for the IETF to
publish drafts that describe simulation results. Such results are typically
presented at scientific conference or published in journals and are
peer-reviewed. Unfortunately, this draft does not provide results that validate
the performance of the proposed technique from a traffic engineering viewpoint.

I have two main concerns about the overall content of the draft.

First, there is no discussion on how the proposed technique would react to link
or node failures although these events are key in many networks.

Second, there is no detailed explanation on how the simulation has been
conducted in terms of traffic matrix, link capacities, ... The graphs provide a
comparison between OSPF and the proposed solution, but the draft does not
explain how the OSPF weights have been computed while there are many techniques
in the literature and in production networks that tune the OSPF weights for
traffic engineering purposes. Ignoring these existing techniques is misleading.

I do not consider that this draft brings useful information about the
technology described in the companion documents.

---

From: "Aijun Wang" <[email-masked]>
Date: Sat, 28 Sep 2019 11:14:40 +0800

Hi, Olivier:

Thanks for your review and comments.
The main aim of this draft is to illustrate the scenarios that are useful
for the TE in Native IP network. It is the base document for the following
two drafts:
https://datatracker.ietf.org/doc/draft-ietf-teas-pce-native-ip/ (Solution
document)
https://datatracker.ietf.org/doc/draft-ietf-pce-pcep-extension-native-ip
(PCEP extension document)

The simulation part of this draft just want to express that we have finished
the algorithm that can compute the E2E optimal path based not only on the
IGP metric, and also the algorithm to eliminate the temporal congestion in
the simulated network. The simulated network is the same size and complex as
our real network, also the traffic matrix distribution. 
The detailed algorithm can be found at another
paper(https://ieeexplore.ieee.org/document/8657733 " A Practical Traffic
Control Scheme With Load Balancing Based on PCE Architecture ") that I will
refer to it in upcoming update version.

The link or node failures consideration will be covered in the solution
draft. Mike from Cisco gives also us some thoughts on this aspect.

I will update the draft in recent days, wish it can give you more
information for your concern.

Thanks in advance.

Best Regards.

Aijun Wang
China Telecom

-----邮件原件-----
发件人: [email-masked] [mailto:[email-masked]] 代表 Olivier
Bonaventure via Datatracker
发送时间: 2019年9月28日 3:57
收件人: [email-masked]
抄送: [email-masked]; [email-masked];
[email-masked]
主题: [Teas] Tsvart last call review of
draft-ietf-teas-native-ip-scenarios-08

This document has been reviewed as part of the transport area review team's
ongoing effort to review key IETF documents. These comments were written
primarily for the transport area directors, but are copied to the document's
authors and WG to allow them to address any issues raised and also to the
IETF discussion list for information.

However, as a researcher with some knowledge of traffic engineering
techniques, I'm surprised by the content of the draft. It is unusual for the
IETF to publish drafts that describe simulation results. Such results are
typically presented at scientific conference or published in journals and
are peer-reviewed. Unfortunately, this draft does not provide results that
validate the performance of the proposed technique from a traffic
engineering viewpoint.

First, there is no discussion on how the proposed technique would react to
link or node failures although these events are key in many networks.

Second, there is no detailed explanation on how the simulation has been
conducted in terms of traffic matrix, link capacities, ... The graphs
provide a comparison between OSPF and the proposed solution, but the draft
does not explain how the OSPF weights have been computed while there are
many techniques in the literature and in production networks that tune the
OSPF weights for traffic engineering purposes. Ignoring these existing
techniques is misleading.

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

---

From: Olivier Bonaventure <[email-masked]>
Date: Sun, 29 Sep 2019 15:53:26 +0000

Hello,

> our real network, also the traffic matrix distribution.

I would then suggest to simply reference this published paper in one of 
the two main drafts and not summarise the paper content in the third draft.

Olivier