RE: A question on how to use the IPERF tool on links with asymmetric speeds
> >Date: Mon, 28 Oct 2002 06:35:35 -0800 (PST)
> >
> >Dear Sir,
> >
> >
> >A simple question :
> >Can IPERF be used to measure and report bandwidth on a
> >link with asymmetric speeds ?
Yes. The current version only tests bandwidth in one direction, from the
client to the server.
> >I have several sites that are interconnected through a
> >providers MPLS network.
> >
> >The routers on the my sites are connected via a FWA
> >(Fixed Wireless Access) link to the routers at the
> >edge of MPLS.
> >
> >The characteristics of the used FWA's are 1Mpbs/4Mbps
> >and 8Mbps/8Mbps (upward/downward). Upward being from
> >my site to the MPLS-cloud.
> >
> >Can IPERF help me measure speeds in this environment?
> >
> >
> >
> >[siteA]<-- 8/8 -->( MPLS cloud )<-- 1/4 -->[siteB]
> >
> >I a perfect world the bandwidth
> > from siteA to siteB would be 4 Mpbs.
> > from siteB to siteA would be 1 Mpbs.
Well to test against the perfect world you can run a UDP connection at the
max bandwidth and see what kind of loses you encounter.
siteA: iperf -s -u
siteB: iperf -c siteA -u -b 1M
siteB: iperf -s -u
siteA: iperf -c siteB -u -b 4M
Or if you read the documentation it will show you how you can tune a TCP
connection to get the most out of a connection.
Kevin
--
Mitch Kutzko | mitch --at-- dast.nlanr.net | mitch --at-- ncsa.uiuc.edu | 217-333-1199
http://hobbes.ncsa.uiuc.edu/