Bandwidth throttling with Robocopy
June 28, 2012 2 Comments
If you need to copy data between Windows systems but have limited bandwidth, and don’t want to consume it all, ROBOCOPY has a useful switch which allows you to do just that.
The switch is /IPG (Inter Packet Gap), and there’s a formula for calculating the gap (in milliseconds) which is most appropriate for use depending upon your available bandwidth:
The following formula expresses the delay (D, in milliseconds) required to simulate a desired bandwidth (BD, in kilobits per second), over a network link with an available bandwidth of BA kbps:
So, for example, on a 4Mbps line, you could throttle down a copy to use a maximum of 2Mbps by using the/IPG:125 switch.
ROBOCOPY is installed by default on Windows 2008 / 7 or later, and is available as an optional download for older operating systems. Further reading can be found at http://en.wikipedia.org/wiki/Robocopy#Bandwidth_throttling.