Does anyone know of bootable Linux CD with iperf on it? Frank
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] 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 <[EMAIL PROTECTED]> 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 > [EMAIL PROTECTED] > > > 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 > > [EMAIL PROTECTED] > > > 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