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Hey
I'm developing a database application for a client who is using a sattelite internet connection. this will obvisouly cause a delay in data transfers between the app and the database and I'm looking for a way to emulate the environment in order to test performance issues.
If anybody has heard of anything that would allow me to do this then please let me know!
Change the NIC from auto, 100 full to 10 half ?
Create a dial-up connection, connect at 9600, 4800, 2400 ?
This might be close
Quote:
Originally Posted by r_barlow
More than likely you program is going to multi-threaded since your read and writes along with your data processing are going to have to wait on network latency.
To simulate network latency, simple call the threading sleep function. It will be different for every language. The article below will cover everything in the .Net world.
http://msdn2.microsoft.com/en-us/lib...ep(VS.71).aspx
You can do this with a single thread as well, but you entire program will sleep, not using a reader or writer thread.
There is a nice example of doing a single threaded AJAX.net application and introducing network latency in a video by microsoft.
http://ajax.asp.net/default.aspx?tabid=47
However, I done method many times to simulate network protocol interaction while introducing random network latency.
Adding delays won't help.
TCP over a satellite link has unique challenges. The important delays would have to be simulated below the protocol stack. I'm not sure most people are aware of the ACK, retry, and TCP Windowing issues involved.
http://www.tkn.tu-berlin.de/curricul...7/schilke.html discusses some of this.
You need a network delay and impairment box like that described at http://www.isi.edu/nsnam/ns/
i have written code to simulate the delays in the tcp/ip stack, etc.
took me a week, but in deed it is possible.