TCP/IP has expienced many changes due to it’s growth in use over the years. Some features help with Networking while posing a hindrance in performance to the virtual machine.

One feature that is disabled for Windows 7 is “Compound TCP.” CTCP is more agressive with the TCP send window. It attempts to increase throughput by monitoring delay and packet loss.

You might see an increase in performance if you enable this feature.

As always test a change like this. Run a test job a couple times to get an estimated run time.

You will need administrative level access and the netsh utility is used to make this change:

netsh int tcp set global congestionprovider=ctcp

If you find it doesn’t do anything, you can go back to the system default with the following command:

netsh int tcp set global congestionprovider=default

So far ctcp has helped and in a couple cases it’s contributed to significantly reduce run times.