Enabling ECN (Explicit Congestion Notification) which is now included in the TCP/IP stack for Windows Server 2008

What is ECN?
Explicit Congestion Notification (ECN) is an extension to the Internet Protocol and is defined in RFC 3168 (2001). ECN allows end-to-end notification of network congestion without dropping packets.The Addition of Explicit Congestion Notification (ECN) to IP, states that with the addition of active queue management (for example, WRED) to the Internet infrastructure, routers are no longer limited to packet loss as an indication of congestion.

ECN and Windows Operating Systems
ECN has now been added to the TCP/IP stack in the following Windows Operating Systems:

1. Windows Vista
2. Windows 7
3. Windows Server 2008

How do we enable ECN is Windows Operating System?

1. Open a command prompt as an adminstrator
2. Type "netsh int tcp show global"this will show your current TCP/IP state
3. To enable ECN, in command prompt type:"netsh int tcp set global ecncapability=enabled"
4. To enable CTCP (Compound TCP)in command prompt type:"netsh int tcp set global congestionprovider=ctcp"
5. To verify changes Type "netsh int tcp show global"