for testing application performance at different network latency scenarios.
Tools/Technology Used:
DummyNet
{Home}URL: http://info.iet.unipi.it/~luigi/dummynet/
Background:
Normally the difference which comes in development and deployment
environment of Web Applications, is of bandwidth and latency.
To test the applications in actual scenario, one needs to tweak the latency as
per deployment scene and then use it.
There are few paid VE Technology based services like "Shunra" for this. But
we required a free, open-source application, if possible for windows.
DummyNet, it's an old Italian university project started for BSD systems,
recently ported for Windows also. It helps in reducing latency of NIC to
desired level.
Execution Method:
[] Install NDIS Driver
1. Open the configuration panel for the network card in use
{right click on the icon on the SYSTRAY, or go to 'Control
Panel' > 'Network' to select}
2. Click on 'Properties' > 'Install' > 'Service' > 'Add'
3. Click on 'Driver Disk' and select 'netipfw.inf' in the
folder it has been extracted to.
4. Select 'ipfw+dummynet' which should be the only service
visible.
5. Click 'Accept' on the warnings for the installation of an
unknown driver.
Create a BAT-File for your Application to be run under test bandwidth &
latency with following content
--------------------------------------File Content Starts from Next line
@echo off--------------------------------------File Content Ends at Previous line
@set CYGWIN=nodosfilewarning
@ipfw -q flush
@ipfw -q pipe flush
@echo #################
@echo ## Setting up ##
@echo #################
ipfw pipe 3 config delay 1000ms bw 500Kbit/s mask all
ipfw add pipe 3 ip from any to any
ipfw pipe show
@echo ""
@echo "Network Tweaking Done, Start Testing."
@echo ""
@echo "Press Enter when testing is done, to restore original Network Settings."
pause
@echo #################
@echo ## Cleaning up ##
@echo #################
ipfw -q flush
ipfw -q pipe flush
pause
Here, 1000ms is latency set and can be changed to desired value
500 Kbps is bandwidth set and can be changed to desired value
'delay x' and 'bw x'; both can be used separately also as per need
either place a command running your application to be tested in place of
'your_command_running_your_app'; or simple remove that line
and when the command gets paused at the first pause, run your appl ication
manually.
Installation:
Follow the wlak-through video on Youtube at :
http://www.youtube.com/watch?v=jP-DrxTMXDc
Then, to test if it gets installed properly as a network services. It has a testme.bat file showing different tests, just run it and
check statistics.
I tested it on Windows XP, Vista, 7... and it worked great.
