Configure Broadband Connections Using RASPPPoE in XP.

Some broadband Internet service providers identify your computer on their networks using Point to Point Protocol over Ethernet (PPPoE). If your ISP requires you to supply a name and password to access the Internet, it most likely uses this protocol.

Those ISPs provide you with software to enable the protocol on your computer. In some cases, this software has not been updated for Windows XP. However, you can still use the broadband connection because Windows XP requires no additional software to enable PPPoE. Support for this protocol has been added to the operating system. You can use the software provided by your ISP, or you can use the integrated support in Windows XP.

Note If the software provided by your ISP has not been updated for Windows XP, you will see an error message when upgrading your operating system, or when you try to install the software after upgrading to Windows XP. You should then ask your ISP for a version that is compatible with Windows XP or use the built-in PPPoE support to create a broadband connection.

To configure Windows XP for a broadband connection using RASPPPoE

1. Click Start, click Control Panel, click Network and Internet Connections, and then click Network Connections.

2. Under Network Tasks, click Create a new connection, and then click Next.

3. Click Connect to the Internet, and then click Next.

4. Click Setup my connection manually, and then click Next.

5. Click Connect using a broadband connection that requires a user name and password.

6. In the Connection Name dialog box, type the name of the ISP. This becomes the name of the connection. Click Next.

7. In the Internet Account Information dialog box shown in Figure 1 below, type the user name and password. Additional checkboxes allow you to specify whether this connection and its user name and password is available to all users (selected by default), whether this connection is your default Internet connection (selected by default), and whether to enable the Internet Connection Firewall on the connection (enabled by default). Make the appropriate selections, and then click Next.



8. In the Completing the Connection Wizard dialog box, review the settings. If you need to modify any of them, click Back as many times as necessary. If all the settings are correct, click Finish.

9. In the Connect dialog box, click Connect to attempt the connection.

    

PPPoE Service Names

Windows XP is designed so that you do not need to configure a PPPoE service name. Windows XP attempts to discover the service name automatically during the connection. This works for most users. If a specific service name is required

1. Open Network Connections, right-click on your broadband connection, and then click Properties.

2. On the General tab, enter the service name, then click OK.

Maximum Transmission Unit

There is no ability to configure the maximum transmission unit (MTU) of the PPPoE connection from the properties of the connection. By default, a Windows XP PPPoE connection uses an MTU size that is 20 bytes less than the IP MTU of the LAN adapter over which the PPPoE packets are sent, which in most cases is 1480 bytes. The 20 bytes of overhead consist of the PPPoE header (6 bytes), the largest possible outer PPP header (4 bytes), the largest possible Multilink PPP header (4 bytes), the largest possible PPP header for compression and encryption (4 bytes), and the PPP header that identifies the actual packet being sent (2 bytes).

If a lower MTU is required, then do one of the following:

• Instruct your ISP to configure their access devices to negotiate a lower MTU using the PPP maximum receive unit (MRU) option. This the recommended solution.

• Or, manually change the MTU size for all non-VPN miniports by setting the following registry values on the computer running Windows XP. (This will change the MTU size for the Windows XP PPPoE miniport.) Change:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NdisWan\Parameters\Protocols\0\ProtocolType to 0x0800.

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NdisWan\Parameters\Protocols\0\PPPProtocolType to 0x0021.

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NdisWan\Parameters\Protocols\0\ProtocolMTU to the required MTU size. PPPoE will use the lesser of this value and the default (the LAN adapter MTU less 20).
    (The second solution is not recommended because it affects the MTU used by all miniports except the built-in VPN miniports.)

Compatibility with Third Party PPPoE Products

There are known compatibility issues with some PPPoE software, including WinPoET version 2.1a or earlier, Enternet 300 version 1.34 or earlier, and RASPPPoE. If updated third-party components are not yet available, you can use the PPPoE client included with Windows XP as an interim solution to obtain Internet connectivity.