Windows XP Modem Tweak Guide

Last Updated on January 23, 2002 by Thomas McGuire

Windows XP much like ever other Windows Operating System offers several improvements over the previous release (Most of the time) & Windows XP is no exception, offering some nice updates to the Networking features. This guide will take you through optimizing the performance, reliability & security of your Dial-up connection in Windows XP as well as several other tips.

Internet Connection Setup

Click on Start, Control Panel, then Network Connections. Right click on your Internet connection & select Properties. Then select Configure button.

Maximum speed (bps). Users of 33.6K Modems should set this to 56700, while 56K Modem users should select 115200.

Enable hardware flow control. Tick this setting to enable the use of hardware handshaking with your connection. For best connection stability & throughput ensure this setting is Ticked. Though in some (rare) cases you may find Unticking this setting can improve connection stability (Uses Software flow control instead).

Enable modem error control. Tick this setting to enable the use of Modem error control, which will attempt to ensure data integrity in the connection, resending any damaged packets as necessary. I’d highly recommend enabling this. There are also Init strings available which can be used to disabled inefficient error control components.

Enable modem compression. Data compression provides faster uploads/downloads depending on the data which is getting compressed. Should you have a Winmodem then you can leave this setting Unticked as these Modems do not support hardware compression. For regular, hardware, modems Tick this setting to enable the Modem to perform any data compression, which provides lower CPU usage over using software compression. As a result I’d recommend Ticking this setting for best system performance.

Show terminal window. Tick this setting to have a Pre-dial terminal session appear. If you need to use this you’ll know. I can’t think of any modern ISP that would require you to use something archaic like this, though some more advanced users might use this to test the Modem. For everyone else just leave this Unticked.

Enable modem speaker. Tick this setting to enable the speaker on the Modem to emit sound. This is fairly useful as you should be able to tell whether or not you can successfully connect or not just by listening to the connection when being dialled up. Untick this setting to mute the Modem’s speaker.

Click Ok & select the Networking tab.

Type of dial-up server I am calling. Set this to PPP: Windows 95/98/NT4/2000, Internet unless your ISP has informed you otherwise, which is unlikely.

Now select the Settings button.

Enable LCP extensions. LCP (Link Control Protocol) extensions provide a way of establishing, configuring, maintaining, & terminating a PPP connection. You should leave this setting Ticked unless you experiencing problems connecting to your ISP as a result of its enabling.

Enable software compression. Tick this setting to enable software (CPU) data compression for your connection. This will provide faster uploads/downloads depending on the data which is getting compressed. Should you have a Modem which can performance compression in hardware then I’d recommend you leave this setting Unticked & allow the Modem to perform any data compression – this should improve system performance slightly as the CPU will not be required to perform a task which can be done on separate, dedicated, hardware. Those would Winmodems should Tick this for optimal upload/download speeds, albeit it at the cost of some CPU cycles.

Negotiate multi-link for single link connections. You can leave this setting Tick unless you experience problems connecting to your ISP (Error code 733 according to Microsoft), in which case Untick this.

Click Ok after you’ve made your changes.

For the most efficient Internet connection you should Uninstall as many unnecessary Clients/Services/Protocols as possible, e.g. Client for Microsoft Networks & QoS Packet Scheduler. As you may have noticed from my Dial-up connection only Internet Protocol (TCP/IP) is installed.

Select Internet Protocol (TCP/IP) & then the Properties button.

Should you have been assigned a static IP address by your ISP (Highly unlikely) use sure to select Use the following IP address & enter in the address you have been assigned with, otherwise just leave this set to Obtain an IP address automatically.

Now select the Advanced button.

Use default gateway on remote network. Tick or Untick this setting as per the description.

Use IP header compression. Leave this Ticked for best connection performance, although many who play Multiplayer Games online have reported that Unticking this improves ping times slightly.

Now select the DNS tab.

Adjust the settings here as directed by your system administrator or ISP. Although for those of you with stand-alone PCs you can adjust the settings here to disable the use of the DNS & DCHP Client (Which should reduce Memory usage slightly). To configure the settings in this tab for this please check this page & the page after of our Windows XP Services Guide.

Now select the WINS tab.

WINS addresses. Add/Remove WINS server addresses here as directed by your system administrator or ISP.

Enable LMHOSTS Lookup. Tick this setting if you have set NetBIOS setting to Enable NetBIOS over TCP/IP or Default, otherwise Untick this setting.

NetBIOS setting. For improved security online it is recommended to set this to Disable NetBIOS over TCP/IP (You can also disable the TCP/IP NetBIOS Helper service as a result), although change this to either of the other available settings if directed to do so.

Click Ok 2 times after you’ve finished making your changes & restart as requested. Should you wish to use the built-in Windows XP firewall select the Advanced tab & enable it. Personally I’d recommend using something like ZoneAlarm instead as it’s easier to use but that’s up to you.

Modem Configuration

Click on Start, Control Panel, then Phone & Modem Options & select the Advanced tab.

Similar to the Networking tab for your Internet Connection you should Remove all unnecessary components from here as well. Use the Add button to restore an uninstalled telephony provider should it be required in the future.

Now select the Modems tab, then select a listed Modem & hit the Properties button (If you have multiple Modems installed then you’ll need to repeat these steps on each device). Now select the Modem tab.

Speaker volume. Adjust this as you feel necessary. There’s no need to make any adjustments if you previously Unticked Enable modem speaker.

Maximum port speed. This setting specifies the maximum Port speed that can be used with the installed Modem. Similar to before users of 33.6K Modems should set this to 56700, while 56K Modem users should select 115200. Those with some other Modems may wish to use higher values though it’s unlikely your Modem will support it, e.g. the later revision of the Courier V. Everything Modem supports a 230400 Port speed.

Dial Control. Leave this setting Ticked unless you have to use an unusual way to dial-up your connection (Or the modem can’t acknowledge the dial tone for some reason).

Now select the Advanced tab.

Extra initialisation commands. Should you wish to do so you can enter in an optional Init string into this field. You can find a listing of such strings for various Modems at 56K.com. Be sure to look out for Init strings that;

Disables MNP 2 – 4 error correction.

Disables MNP 5 data compression (Hardware Modem only).

This will further optimize your Internet connection as it disables outdated protocols.

Country/Region Select. Unsurprisingly enough use this drop-down menu to select the country which you are residing in, this may be limited by the Modem you have installed.

Now select the Advanced Port Settings button.

Use FIFO buffers. If you have an internal Modem leave this Ticked, similarly leave this Ticked if you have an external Modem although if you have a very old Motherboard you may need to modify the Receive Buffer & Transmit Buffer sizes or Untick this to fix connection problems (Although if you have a Motherboard with such an old Serial port it’s likely your system doesn’t meet the Minimum recommended specifications for Windows XP either).

Receive Buffer & Transmit Buffer. These sliders control the size of the receive & transmission buffers. For best connection performance set this to 14 & 16 respectively. You shouldn’t need to reduce either of these buffer sizes (Though some recommend you do for performance reasons, which I wouldn’t).

COM Port Number. You shouldn’t need to adjust the COM port your Modem is installed onto unless perhaps another Hardware installation somehow affected your Modem’s. NOTE – If you have an internal Modem installed do not adjust this value to be the same as a COM Port listed in Device Manager (Internal Modems only emulate a COM Port & don’t use a real one).

Click Ok again & then select the Change Default Preferences button.

Port speed. This setting specifies the maximum Port speed that can be used with the installed Modem. Similar to before users of 33.6K Modems should set this to 56700, while 56K Modem users should select 115200. Those with some other Modems may wish to use higher values though it’s unlikely your Modem will support it, e.g. the later revision of the Courier V. Everything Modem supports a 230400 Port speed.

Data Protocol. Setting this to Standard or Forced EC will enable the use of Modem error control, which will attempt to ensure data integrity in the connection, resending any damaged packets as necessary. For optimal performance set this to Forced EC rather than Standard as this will disable MNP 2 – 4 error correction, which are less efficient error correction protocols than V. 42 is. Though if this causes some problems set this to Standard instead.

Compression. Data compression provides faster uploads/downloads depending on the data which is getting compressed. Should you have a Winmodem set this to Disabled as these Modems do not support hardware data compression. For regular, hardware, Modems set this to Enabled to enable the Modem to perform any data compression, which provides lower CPU usage over using software compression. As a result I’d recommend enabling this setting for best system & Internet connection performance.

Flow control. For best connection stability & throughput set this to Hardware to enable the use of hardware handshaking with your connection. Though in some (rare) cases you may find setting this to Xon / Xoff (Software flow control) can improve connection stability.

Now select the Advanced tab.

Data bits, Parity & Stop bits. Do not check any of these values from their defaults – 8, None & 1 unless directed to do so by your ISP.

Click Ok twice after you’ve made your changes.

Registry Settings

For the most part Windows XP is highly capable of determining connection properties such as the optimal MTU (Maximum Transmission Unit) to be used & such. Though you can always set these yourself if you wish.

Click on Start, Run, type regedit & hit enter. Open the following registry key, [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Paramters]. Add/Edit the following New DWORD values in the right hand pane as you see fit.

DefaultTTL. This sets the number of hops a packet is allowed to pass between you & it's intended destination. I’d recommend setting this to a Decimal value of 64, or perhaps 128 (This won’t affect performance).

EnablePMTUDiscovery. When set to 1 Windows XP will automatically determine the MTU size to use. A value of 0 will disable this & is recommended if you wish to manually determine the MTU to use.

EnablePMTUBHDetect. A value of 1 enables black-hole detection on your Internet connection. This isn’t recommended unless you are experiencing connection problems & is probably an indication of some problem with your ISP. Such you have a decent Internet connection or better set this to 1.

Should you now wish to manually set the MTU to use you’ll first need to determine the value to use. Once connected to the Internet open a new Command Prompt window. To calculate the MTU type in ping –f –l x www.isp.com & hit Enter. Replace x with a numeric value ranged from about 500 to 1500. Replace www.isp.com with the address of your ISP, or if available use the IP address of the Server you have connected to, to get online.

Replace the numeric value (x) with different (higher) values until the message Packet needs to be fragmented but DF set. Once this message appears reduce the x value by 1 until the message disappears. Once it has, take this value & Add 28 to it, then write it down, e.g. if the value used was 1472 then adding 28 to it will give a final value of 1500 – which will be your MTU.

Now open regedit & go to the following registry key, [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Paramters\Interfaces]. Add the following New DWORD value in the right hand pane.

MTU. Select the Decimal button & enter the value you have just calculated into the Value data field. You’ll need to reconnect, or reboot (preferably) for the changes to take effect.

Improving Security

The first thing to do if you want to have a more secure system when connected to the Internet is to install a Firewall. Probably the most popular at the moment (& the one that I use) is Zone Labs ZoneAlarm (Available in Free & Pro versions), which is simple enough to configure (Compared to, say the Windows XP built-in Firewall).

Next up is to ensure you’ve installed available Security patches for both Windows XP & installed Applications. You can do this via Windows Update, Catchup or BigFix which will detect various such product updates. That & we post up links to all the latest security updates as they get released by Microsoft.

Adjusting your Services settings can also close other potential security holes as well. You can find out about all of these in our Windows XP Services Guide. Similarly our Internet Explorer 6 Tweak guide will show you how to more securely configure that as well for browsing.

Game Multiplayer Settings

Should you wish to find out how to further optimize the performance of your Internet connection in Multiplayer Games online be sure to check out our extensive Game Tweak Guides section. These will show you all the Menu/Configuration settings you need to know to get the most out of the Multiplayer in these Games, such as using bindings or disabling unneeded protocols to improve ping times & such.

Conclusion

By now you should have successfully configured your Dial-up Internet Connection in Windows XP for a combination of reliability, performance & security. This guide may be updated in the future with further information. Should you have any problems be sure to check our Everything Hardware or Software Forum. You can email me with any suggestions you may have.

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