Subject: [Pce] Jari Arkko's Yes on draft-ietf-pce-pcep-service-aware-12: (with COMMENT)

From: "Jari Arkko" <[email-masked]>
Date: Thu, 15 Sep 2016 00:23:28 -0700

Jari Arkko has entered the following ballot position for
draft-ietf-pce-pcep-service-aware-12: Yes

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COMMENT:
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The document should probably say more about how frequently information
can be updated and recomputation can occur; there's a possibility that
too frequent adjustment creates a flip flop effect where traffic moves to
a new path, performance degrades, etc.

I was curious about the definition of the P2MP packet loss as being the
highest among the individual path losses. Is there some basis in some
measurement documents for instance for this definition? It would seem to
me that other definitions would also be possible, e.g., ones that take
the aggregate loss into account in some fashion.

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From: Dhruv Dhody <[email-masked]>
Date: Thu, 15 Sep 2016 16:04:42 +0000

Hi Jari, 

Thanks for your comments, please see inline...

> -----Original Message-----
> From: Pce [mailto:[email-masked]] On Behalf Of Jari Arkko
> Sent: 15 September 2016 12:53
> To: The IESG <[email-masked]>
> Cc: [email-masked]; [email-masked];
> [email-masked]
> Subject: [Pce] Jari Arkko's Yes on draft-ietf-pce-pcep-service-aware-12:
> (with COMMENT)
> 
> When responding, please keep the subject line intact and reply to all email
> addresses included in the To and CC lines. (Feel free to cut this introductory
> paragraph, however.)
> 
> 
> Please refer to
> https://www.ietf.org/iesg/statement/discuss-criteria.html
> The document should probably say more about how frequently information can
> be updated and recomputation can occur; there's a possibility that too
> frequent adjustment creates a flip flop effect where traffic moves to a new
> path, performance degrades, etc.
> 
[Dhruv] I have added this text in the section 1 - 

   [RFC7471] and [RFC7810] describe various considerations regarding -

   o  Announcement thresholds and filters

   o  Announcement suppression

   o  Announcement periodicity and network stability

   The first two provide configurable mechanisms to bound the number of
   re-advertisements in IGP.  The third provides a way to throttle
   announcements.  Section 1.2 of [RFC7823] also describes the
   oscillation and stability considerations while advertising and
   considering service aware information.

> I was curious about the definition of the P2MP packet loss as being the highest
> among the individual path losses. Is there some basis in some measurement
> documents for instance for this definition? It would seem to me that other
> definitions would also be possible, e.g., ones that take the aggregate loss
> into account in some fashion.
> 

[Dhruv]: I do not have a reference for this, it just made good intuitive sense to go this way during discussion with authors/WG while considering packet loss for P2MP TE. Other definitions are possible, and can be added by defining new OF/metric in future.   

Let me know if you would like to see further change. 

Regards,
Dhruv  

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From: Jari Arkko <[email-masked]>
Date: Thu, 15 Sep 2016 19:08:25 +0300

Thanks. This all makes sense.

Jari