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