Measuring Performance of IP Traffic

[purplebroom]

Hi

We have installed a satellite comms sysytem at a remote site to provide broadband internet access and VPN connection to our main network. As part of the analysis of this trial we would like to test the performance of the IP traffic form the satellite system.

Can anyone recommend a good, free, simple product that will test for latency, jitter, dropped packets, overheads etc.. and provide graphical\statistical output. I know there are thousands out there but most are either too elaborate or take a whole year to learn how to use... Would also be helpful if someone could point me to any reference information for benchmarking comparison.

thanks for any help

P-Bro

"IT is like going to the toilet... the job aint complete till the paperworks done!!"

 

[bcastner]

http://www.dslreports.com/tweaks

You can use the Performance Monitor in XP or Win2k for dropped packets and I/O measures:

http://support.microsoft.com/defaul...port/kb/articles/Q222/1/93.ASP&NoWebContent=1

 

[mpennac]

Two free tools that are out on the market for measuring IP throughput are QCheck and Iperf. QCheck is a graphical tool that will allow you to transfer up to 1 meg of data between two endpoints. It will report back the throughput between those two devices. It can be found at

http://www.qcheck.net.

Iperf is a command line tool that allows you to measure throughput between two devices also. A couple of the advantages of Iperf is that you don't have to install the endpoint service and you can change the TCP Windowsize without rebooting. You can search the Internet for Iperf and you will find several sites where you can download it.

One of the key factors in achiving good throughput on a satelite link is the TCP Windowsize. This defines the receive buffer for each TCP connection. If you don't increase this window size above the default values, you won't be able to fully utilize that satelite link. With Iper you can try different window sizes to see what works best. Win2K and WinXP allow you to use scalable windows. This provides window sizes up to 1 gigabyte. I have a video tip on my website that shows how to change the TCP Windowsize.

Another limiting factor on satelite links is the number of HTTP connections that HTTP 1.1 allows at one time. The recommeded value is 2. This means you can only have 2 outstanding HTTP requests to a server at one time. We have reduced the load time for websites from 50 seconds to 8 seconds by increasing the number of concurrent connections. This can be done through the registry. I don't have the key right now, but I will follow this reply up with the registry entry.

Hope this helps,

Mike

http://www.netprospecialists.com