If you need to copy data between Windows systems but have limited bandwidth—and don’t want to consume all the data pipe—ROBOCOPY has a useful switch which allows you to throttle bandwidth.
The switch is /IPG (Inter Packet Gap). 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.