Subject: Paper on passive RTT estimation

From: Andrew Mcgregor <[email-masked]>
Date: Thu, 20 Jul 2017 17:49:49 +0200

I mentioned a technique for measuring RTT passively at the mic today. This
paper is an example of a technique for doing so:
http://www-sop.inria.fr/members/Philippe.Nain/PAPERS/PASSIVE-ONLINE-ESTIMATION/Passive-online-RTT-estimation.pdf

There are undoubtedly others, although that is powerful enough to be
sufficient for most network management purposes.

-- 
Andrew McGregor | SRE | [email-masked] | +61 4 1071 2221

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From: Christian Huitema <[email-masked]>
Date: Thu, 20 Jul 2017 22:58:09 -0700

Very nice paper. In short, they observe that the "one update per RTT"
nature of TCP congestion control causes the traffic to exhibit
noticeable periodocity. They then use a filtering technique to estimate
the corresponding period, which is the RTT. This is done by observing
just one direction of traffic.

It would be good to get someone to independently reproduce the
experiment and validate the method, and verify in particular that it
applies to different congestion algorithms (BBR) and that it can detect
short term variations in the RTT, such as transient congestion.

-- Christian Huitema

On 7/20/2017 8:49 AM, Andrew Mcgregor wrote:
> I mentioned a technique for measuring RTT passively at the mic today.
> This paper is an example of a technique for doing
> so: http://www-sop.inria.fr/members/Philippe.Nain/PAPERS/PASSIVE-ONLINE-ESTIMATION/Passive-online-RTT-estimation.pdf
>
>
> Andrew McGregor | SRE | [email-masked]
> <mailto:[email-masked]> | +61 4 1071 2221