nanog mailing list archives

RE: Bandwidth issues in the Sprint network


From: "Frank Bulk" <frnkblk () iname com>
Date: Thu, 10 Apr 2008 12:17:25 -0500


I tried this on three laptops (two different models), and none of them would
fully boot.  They would lock up at different points.

Unless someone has some workarounds, I think I'll be trying another ISO
package.

Regards,

Frank

-----Original Message-----
From: Tim Peiffer [mailto:peiffer () umn edu] 
Sent: Wednesday, April 09, 2008 9:50 AM
To: frnkblk () iname com
Cc: nanog () merit edu
Subject: Re: Bandwidth issues in the Sprint network

http://e2epi.internet2.edu/network-performance-toolkit/network-performance-t
oolkit.iso

Frank Bulk 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



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