network

[pravin_ye]

"hello..i am using separate intranet in my campus with cisco switches with opticfibre
i want to know the bandwidth of our network ..is there any comma..."

[DaveLembke]

I have tested bandwidth on LAN's with copying a large file from one system to another and then calculating the time it took to process. As a stop watch you can simply have a large file on a system on your LAN that is at a shared location, and then process a batch file that downloads the file from the file share to the local system at which the batch is run from, your batch will have a Date / Time stamp at the beginning of the process and then it will have a Date / Time stamp at the end of the process that is written to a log file. You then open the log file to see what it recorded for start and stop times and then figure out how long it was running. Then divide the size of the file by the time it took to download and you have your bandwidth speed calculated between the 2 systems.

*Note: You will want to do this with the 2 fastest systems you have that are idle and not busy with LAN traffic, you also would want the LAN traffic to be quiet so that you are measuring the actual bandwidth that is not competing with other traffic and skewing the results to look as if you have slower bandwidth because of network conjestion.

Here is an example of how I have done this in the past. Z: is the mapped drive to the shared location on the system that is hosting the large file for download for this test. C: is your local systems drive to where the download will copy to. There is a folder on C: called lanspeedtest for the log and the large file to copy to. largefilename.ext is replaced with the name of the large file that is copied.

Code: [Select]

cd\.
z:
@echo. Transfer Started ... Please Wait
@echo. Transfer Started at %time% on %date% >>C:\lanspeedtest\transferlog.log
xcopy z:\largefilename.ext c:\lanspeedtest\*.* /y
@echo. Transfer Completed at %time% on %date% >>C:\lanspeedtest\transferlog.log
@echo. Transfer Completed ... You can now close this window and view transferlog times
@echo.
pause

So if you had times of:

Started on       18:09:32.24
Completed on  18:14:39.83

* You can trim the fractions of a second if you like and have:

Started on       18:09:32
Completed on  18:14:39

And this gives us 5:07 ( 5 minutes 7 seconds ) to complete.

If our file transferred was 100MB we just process the math as so:

5:07 = (( 5 x 60 )+7) = 307 seconds

100MB divided by 307 seconds = .3257 MB/second

You then can perform the MegaBytes to MegaBits conversion and end up with 1 Mega-Byte = 8 Mega-Bits ( * 8 Bits = 1 Byte )

So .3257 MB/s x 8 = 2.6058 mbps

Hopefully you have far better numbers than this  ... This is just an example!