GPRS and Remote Access

Traditionally companies have provided remote access for their workers using dial-up modem connections into corporate modem pools. But as companies have established high speed connections to the Internet, and as remote workers have an increasing number of options for connecting to the Internet, companies are now looking to the Internet as a way for their remote workers to access corporate intranets. This is especially effective because most communications applications today work over IP networks -- including many originally designed for modem dial-up connections. It can be highly cost effective to use the Internet instead of making long distance phone calls, and in the case of international connections, much more reliable. But this Internet-based technique does raise an issue of privacy from hackers. A new technology is emerging which addresses privacy and authentication concerns, referred to as a virtual private network (VPN).

A VPN is a method of having private communications across public networks. It adds additional software at each end of the connection -- in our case the mobile computer and the corporate network. This software establishes what are called "tunnels". Within this tunnel, information is encrypted and additional information is added to each packet to prevent tampering. Various standards are available or being finalized to define interoperability between VPN products, including the Point to Point Tunneling Protocol (PPTP), Layer Two Tunneling Protocol (L2TP), SOCKS and IPsec (Secure IP). A wide range of companies already offer VPN solutions today, including router vendors, network software providers, firewall suppliers and companies specializing in this area. Since most VPN solutions are quite flexible in their feature set, corporate IT can choose the level and type of protection desired, such as 56 bit encryption or 128 bit encryption.

Almost all VPN technologies operate independently of the communications link, meaning the same VPN technology will work with a dial-up modem connection, Ethernet connections, ISDN connections and most importantly for us, wireless connections. See figure two.

Figure two: tunneling with VPN technology

Companies using VPNs will be able to smoothly migrate from existing wireless technologies to GPRS. Today their users can make circuit-switched connections to an Internet service provider, and then establish a VPN connection. Once GPRS becomes available, the Internet connection will extend to the mobile computer and the user will no longer need to dial a separate ISP. The net result is wireless connectivity that works hand in hand with VPN technologies to let remote workers easily access corporate resources and to stay in touch with their work teams.