How to configure Layer 2 Tunnel Protocol (L2TP:

Windows XP users

• From the Start Menu, choose Control Panel -> Network Connections ->
•  Make New Connection.
  New Connection Wizard window will appear, and then click next.

• choose connect to the internet at my work place, and then click next..

     * choose Virtual Private Network Connection, and then click next.

• Name for connection: Coolnet Cable, and then click next.

• choose Do not dial the initial connection, and then click next.
• Host name or IP address: 213.57.50.69, and then click next.

• Open the new Coolnet Dialer and choose properties

• Under the Networking panel, choose under the Type of VPN: L2TP IPSec VPN

• Under the Security panel, select Advanced (custom settings). click on Settings button.

• In the Data encryption: choose Optional encryption (connect even if no encryption)
  and in the Logon security choose Allow these protocols and check Unencrypted password (PAP)

• After that IPsec must be disabled by editing the registry file:
  click on Start->Run and type Regedt32
  
• Go to the following folder:
  HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Rasman\Parameters
  right click and choose DWORD value in the new field.

• Value Name: ProhibitIpSec Type: REG_DWORDValue: 1

• Restart computer for new configurations to take effect.