How can I speed up my ADSL line connection?

A. Because TCP/IP is packet based, each time a packet is sent, it must be acknowledged via an acknowledgment packet. This slows down the system. To keep the sender from having to wait for every packet to be acknowledged before sending another one, you can increase the window size (TcpWindowSize) value on the receiver end. Then, the sender can send packets until that value is reached before the receiver needs to send an acknowledgment. To tweak the TCP/IP parameters to increase the window size, you need to manually update the registry:

  1. Start regedit.exe.
  2. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters.
  3. From the Edit menu, select New, DWORD value.
  4. Enter a name of TcpWindowSize, and press Enter.
  5. Double-click the new value, change the Base value to decimal, and enter a value of 32767. Click OK.
  6. Close regedit.
  7. Reboot the machine.

In step 5, you can actually specify a higher value (up to 256000). However, on slow networks, this larger window size means that more data will need to be retransmitted.

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