Bandwidth issues in the Sprint network

Frank Bulk frnkblk at
Thu Apr 10 17:17:25 UTC 2008

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



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

Frank Bulk wrote:
> Does anyone know of bootable Linux CD with iperf on it?
> Frank
> -----Original Message-----
> From: owner-nanog at [mailto:owner-nanog at] On Behalf Of
> Gonnason
> Sent: Wednesday, April 09, 2008 9:05 AM
> To: nanog at
> Subject: Re: Bandwidth issues in the Sprint network
> On Tue, Apr 8, 2008 at 9:19 AM, Brian Raaen <braaen at> 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 at
>>> 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
> but
>>  individual (flows/ip?) test always seem limited.  I would like to know
>>  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 at
>>  >
> 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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