Optimize your broadband cable modem and dsl connection

Windows registry

Not many PC users know this but Windows XP or Windows 2000 are not configured properly to receive broadband speeds. Remember that these operating systems came out at a time when broadband still has not been rolled out in a commercial level. Only the top companies could afford broadband then. In order to maximize your Windows XPs abilities to accept broadband speeds you should make a few minor tweaks to the XP registry. What you should do is to open your registry. Do this by clicking on Start, then click on run. On the box, type regedit and press enter. This will open your registry. Now try to locate the key below. Create the DWORD values because most of these values do not exist yet so you will need to create them by clicking on Edit > New > DWORD Value — and then set the indicated value.

DefaultTTL = “80” hex (or 128 decimal) (The default is 32). Specifies the default time to live (TTL) for TCP/IP packets.

EnablePMTUBHDetect = “0” Specifies whether the stack will attempt to detect Maximum Transmission Unit (MTU) routers that do not send back ICMP fragmentation-needed messages. The default is 0.

EnablePMTUDiscovery = “1” Specifies whether the TCP/IP stack will attempt to perform path MTU discovery as specified in RFC 1191. The default is 1.

GlobalMaxTcpWindowSize = “7FFF” hex (or 32767 decimal) Specifies the system maximum receive window size advertised by the TCP/IP stack.

TcpMaxDupAcks = “2” Determines the number of duplicate ACKs that must be received for the same sequence number of sent data before “fast retransmit” is triggered.

SackOpts = “1” Enables support for selective acknowledgements as documented by Request for Comment (RFC) 2018. Default is 0.

Tcp1323Opts = “1” Controls RFC 1323 time stamps and window scaling options. Possible values are: “0” = disable RFC 1323 options, “1” = window scale enabled only, “2” = time stamps enabled only and “3” = both options enabled.

TcpWindowSize = “7FFF” hex (or 32767 decimal) Specifies the receive window size advertised by the TCP/IP stack. If you have a latent network you can try increasing the value to 93440, 186880, or 372300.

After making the necessary changes exit the registry and restart your PC to let the changes take effect. Take note that some of these optimized settings may not work with all ISP configurations. When this happens, you should revert to the default values.

1 thought on “Optimize your broadband cable modem and dsl connection”

  1. Wow. You sure got that one wrong. Windows2000 and Windows XP are in fact optimized for broadband. Windows 9x was not (Win95, 98 and WinMe) and would benefit from MTU and TCP tweaks.
    Another thing – if you are going to recommend registry tweaks, it would help to know the registry keys that you are editing, otherwise, the entire article is useless.

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