we have a corporate LAN of approx 200 nodes behind a firewall and recently upgraded bandwidth of ISP. Now we want to measure the performance / bandwidth (internet as well file copy perf on local network) OS is windows. How good are the online tools that claim to measure bandwidth like http://www.speakeasy.net/speedtest?

do they really download/upload files? does repeating tests cause any variation in results due to caching?


How good are the online tools that claim to measure bandwidth like http://www.speakeasy.net/speedtest?

I can think of no better tool for telling you how slow the slowest point between you and their test server on the Internet is than those kind of online tools. Of course there's no way to tell for sure how much of the speed you're seeing (or not) is down to your connection...

The one thing these tools appear to be even better at doing than testing internet connection speed is generating random numbers. Just ran a few tests myself, one with the site you linked to on my workstation, one with a site I've used before (speedtest.net) from my workstation (wired connection to my cable router) and a 3rd one from my iphone to speedtest.net (wireless connection to my cable router).

The results were, respectively: ~8Mb/s, 343Mb/s and 12Mb/s. None of those corresponds to the type of connection I've paid for, with 2 being too slow and one being too fast by a considerable degree. I don't think that speaks well for their usefulness.

I'd say uploading and downloading your own test file to space at your ISP (do you have a website with them that you could use?) might be a reasonable test. This is also a fair internal test.


The online tools are as good as your connectivity between the points being tested, I know that's kind of stating the obvious but there isn't really a concrete answer.

If you want to keep an eye on how your bandwidth is being utilized it depends what firewall/proxy you're using - with most "proper" routers/firewalls you should be able to monitor traffic levels (basic bytes in/out) using SNMP, which over time lets you build up utilization stats/graphs.


I work on these types of issues a lot at my job and I really strongly dislike the bandwidth testing sites

A lot of the bandwidth checking sites are hosted by companies trying to sell you their bandwidth which immediately in my mind discredits their results. Other speed test sites become victims of their own success, they might give accurate results until they make a name for themselves for being accurate so more and more people use them which degrades their ability to generate accurate results. The other reason I greatly dislike bandwidth sites is that they really obfuscate the methods they use to generate the results for the most part. If your site tells me I transferred 500kbps of traffic, I would much rather know the details like protocol/port information than just have a website spit out an number.

I prefer using FTP transfers to establish transfer rates. Most ISPs will have an FTP server you can use to test to, you will probably have to call their support lines to get login info, but if you are to this point, you have probably contacted them already.

If for whatever reason FTP won't do what you need to do, you can use a great network performance tool called iperf (or jperf). You can verify pretty much any aspect of network throughput you want to with an iperf test.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.