One of Windows 95’s most important features was the introduction of Dial-Up Networking. Like NT’s RAS remote access tools, Dial-Up Networking lets you connect to a network - whether it’s your office or the whole Internet - or a single PC, over the phone lines as if you had a direct network connection.

Windows 98 takes Dial-Up Networking a stage further, using Point-to-Point Tunnelling Protocol (PPTP) to help you build secure Virtual Private Networks over the Internet. The PPTP standard has been defined by the PPTP Forum, which consists of Microsoft, US Robotics and several manufacturers of remote access systems – the modem banks used by ISPs and large offices. PPTP works by enclosing PPP packets in a standard IP packet, and then sending them over the Internet.

With PPTP, you can treat the whole Internet as the basis for a virtual Dial-Up Networking connection, transmitting all your data to a single specific Internet address that acts as a gateway into a secure network. All the data you send over this connection can be encrypted and compressed to give you the best possible connection – no matter what protocol you’re using, as PPTP works with TCP/IP, NetBEUI and IPX. If you’re connecting to an NT network, a VPN based on Microsoft’s PPTP will even handle NT domains. As you connect to a gateway server, you can even link directly into secure Intranets that use hidden IP addresses.

Using PPTP is very easy, as it appears as a new modem which you can select when setting up a Dial-Up Networking connection. Just choose the Virtual Private Networking Adapter instead of your usual modem. Don’t worry if you can’t find it in the Modems control panel – you can only access the VPN Adapter from Dial-Up Networking. Instead of giving your new connection a phone number, use the IP address or the full Internet name of your destination computer. You won’t need to fill in an STD code! See also Setting up a PPTP connection

You don’t need to be connected to the Internet via a Dial-Up Networking connection to use a PPTP VPN connection. All you need is a working IP network connection, with access to the Internet – so you could use PPTP to create a secure link between two offices or two different companies. You can use a PPTP link over a standard Dial-Up Networking connection to your local ISP, so you don’t have to spend vast amounts on long distance calls to your office’s modems – just connect over the Internet to their PPTP server. Once a secure PPTP connection has been made, your data is encrypted, and as no unauthorised users can access the connection, your office network remains secure.

Don't be worried if once you're running a PPTP connection, and you can't see the rest of the Internet. Microsoft's PPTP connection sets up a specific route for all TCP/IP traffic through your VPN - so any other destinations aren't available. You can access the rest of the net by adding other routes from the MS-DOS prompt, but you'll need to understand how Windows 98 manages IP routing before you make any changes.

There are some limitations to a PPTP-based VPN. You may find that a connection can’t be made through some types of firewall or network proxy. As your PPP packets are both encrypted and hidden inside IP packets there’s also some overhead in both encrypting and decrypting the data – so your PPTP connection will be slower than the equivalent direct Dial-Up Networking connection.

Setting up a PPTP connection

1. From the Start Menu select Programs / Accessories / Communications.
2. Choose "Dial-Up Networking".
3. Click on "Make New Connection".
4. Give it a name, and chose "Microsoft VPN Adapter" from the drop down list.
5. Click next.
6. Type in the name or IP address of your PPTP server.
7. Click next.
8. Your VPN connection is now ready for use.