Re: [Bloat] RRUL for netperf (bad hack)

["Bill Ver Steeg (versteb)" <versteb@cisco.com>]

Lars-

Iperf also has some one-way and two-way delay measurements (or at least the version I used last year did). It also put timestamps in the payload of the packets.

Bill Ver Steeg












-----Original Message-----
From: bloat-bounces@lists.bufferbloat.net [mailto:bloat-bounces@lists.bufferbloat.net] On Behalf Of Eggert, Lars
Sent: Friday, April 17, 2015 10:46 AM
To: bloat
Subject: [Bloat] RRUL for netperf (bad hack)

Hi,

the attached patch is a horrible, horrible, HORRIBLE hack to add some sort of RRUL testing into netperf. I needed something like this for some quick testing and thought maybe someone else can get some use out of it. (I was interested in the delay an application sees on top of a TCP stream, which is not something Toke's excellent netperf-wrapper tool can currently do, AFAIK.)

I've only really used this with stream tests, and it only produces sensible results with a specific request size such as "-r 16384" or something. And I've only used this on Linux.

Basically, this embeds a timeval into the test stream for each block, echoes it back to the sender, and then prints the application-level RTT seen. (It also prints a one-way delay, but that is only sensible to look at for clocks synchronized to an accuracy much better than the network delay.)

Lars