nanog mailing list archives

Re: Bandwidth issues in the Sprint network


From: "Mike Gonnason" <gonnason () gmail com>
Date: Wed, 9 Apr 2008 06:42:37 -0800


A quick search comes up with Scientific Linux, but I cannot provide
any claims to suitability. I have never even heard of it before, but
it is provided as a LiveCD.

http://linux.web.psi.ch/livecd/software.html

-Mike Gonnason

On Wed, Apr 9, 2008 at 6:28 AM, Frank Bulk <frnkblk () iname com> wrote:

 Does anyone know of bootable Linux CD with iperf on it?

 Frank


 -----Original Message-----
 From: owner-nanog () merit edu [mailto:owner-nanog () merit edu] On Behalf Of Mike
 Gonnason
 Sent: Wednesday, April 09, 2008 9:05 AM
 To: nanog () merit edu
 Subject: Re: Bandwidth issues in the Sprint network




On Tue, Apr 8, 2008 at 9:19 AM, Brian Raaen <braaen () zcorum com> wrote:
 > I have been using the Java based versions of the speed test.  At this
 point I
 >  have had some Sprint people get in contact with me so I will see what
 they
 >  find.  Thank you for all your help to everyone.
 >
 >  --
 >  Brian Raaen
 >  Network Engineer
 >  braaen () zcorum com
 >
 > > On Monday 07 April 2008, you wrote:
 >  > I am currently having problems get upload bandwidth on a Sprint
 circuit. I
 >  am using a full OC3 circuit.  I am doing fine on downloading data, but
 >  uploading data I can only get about 5Mbps with ftp or a speedtest.  I
 have
 >  tested against multiple networks and this has stayed the same.
 Monitoring
 >  Cacti graphs and the router I do get about 30Mbps total traffic outbound,
 but
 >  individual (flows/ip?) test always seem limited.  I would like to know if
 >  anyone else sees anything similar, or where I can get help.  The
 assistance I
 >  have gotten from Sprint up to this point is that they find no problems.
 Due
 >  to the consistency of 5Mbps I am suspecting rate limiting, but wanted to
 >  > know if I was overlooking something else.
 >  >
 >  > --
 >  > Brian Raaen
 >  > Network Engineer
 >  > braaen () zcorum com
 >  >
 >

 Most of the speed test sites on the Internet basically issue a HTTP
 GET request to a server and time the download. For upload they utilize
 a HTTP POST via a CGI script and time that. The main issue I have with
 these speed tests is that they only use a single TCP session for data
 transfer, which is fine if you have a large or self adjusting TCP
 window size and a relatively low latency link.

 However for high capacity links, it is unlikely (but possible) that
 you are planning to use a single TCP session and consume all the
 available capacity. Realistically you will have a few dozen
 server/applications/users and produce hundreds/thousands of TCP
 sessions which will fully utilize the link.

 For our PtP customers that have concerns regarding capacity, I
 generally they suggest setup iperf at both ends and run a few tests
 with multiple TCP sessions so they can independently verify. Hopefully
 Sprint will take your concerns to heart and assist you with testing.

 -Mike Gonnason




Current thread: