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From: Hagen Paul Pfeifer <hagen@jauu.net>
To: "Scheffenegger, Richard" <rs@netapp.com>
Cc: bloat <bloat@lists.bufferbloat.net>,
	"aqm@ietf.org" <aqm@ietf.org>, "tsvwg@ietf.org" <tsvwg@ietf.org>
Subject: Re: [Bloat] [tsvwg] [aqm] how much of a problem is buffer bloat today?
Date: Tue, 26 Mar 2013 21:02:16 +0100	[thread overview]
Message-ID: <20130326200216.GB9410@virgo.local> (raw)
In-Reply-To: <012C3117EDDB3C4781FD802A8C27DD4F24ACFA86@SACEXCMBX02-PRD.hq.netapp.com>

* Scheffenegger, Richard | 2013-03-26 17:49:49 [+0000]:

>TCP measures RTT; 
>
>one could create a global histogram of all measured RTTs by TCP (whenever a
>valid measurement is taken), and export that with "netstat -sp tcp"... Of
>course, vastly different paths would be gobbled up together, but when
>investigating specific paths, that should be good enough as a high level
>starting point.

For Linux tcp-probe[1] is your friend. The last colum is the smoothed round trip
time. The port filter is optional and can be 0 to disable filtering. Not sure
if Linux Distribution ship this module by default. But via tcp-probe you get
accurate per-path rtt statistics without any effort (just a few CPU cycles).


Hagen

[1] http://www.linuxfoundation.org/collaborate/workgroups/networking/tcpprobe


  reply	other threads:[~2013-03-26 20:02 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <51408BF4.7090304@cisco.com>
     [not found] ` <8C48B86A895913448548E6D15DA7553B7D020F@xmb-rcd-x09.cisco.com>
2013-03-21 17:50   ` [Bloat] [tsvwg] " Oliver Hohlfeld
2013-03-21 18:01     ` Jim Gettys
2013-03-21 18:14       ` Oliver Hohlfeld
2013-03-21 18:28         ` Jim Gettys
2013-03-21 18:36           ` Dave Taht
2013-03-21 19:08 ` Oliver Hohlfeld
2013-03-21 19:25   ` Mikael Abrahamsson
2013-03-21 20:05     ` Jim Gettys
2013-03-22  4:27       ` Mikael Abrahamsson
2013-03-22  6:00         ` [Bloat] [aqm] " grenville armitage
2013-03-22 13:23           ` Mikael Abrahamsson
2013-03-22 13:31             ` Dave Taht
2013-03-26 17:25         ` Mirja Kuehlewind
2013-03-26 17:49           ` [Bloat] [tsvwg] [aqm] " Scheffenegger, Richard
2013-03-26 20:02             ` Hagen Paul Pfeifer [this message]
2013-03-21 20:04   ` [Bloat] [tsvwg] " David Lang
2013-03-21 20:47     ` Oliver Hohlfeld

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