Virtual Private Networks, Second Edition

VPN Versus RAS

In this section, we explore VPNs as a replacement for RAS services. While RAS is an industry standard remote connection method for thousands of individual users, it is, by its nature, extremely expensive, somewhat unstable, and generally just not fun to deal with from an administrative perspective. Most users connect through long distance calls, which racks up huge bills for even small RAS services. And the modem-as-network-device has never been stable enough to count on for critical services. Incoming lines, modems, and other such equipment become a network manager’s nightmare. The VPN, with all its weaknesses, has the strength to supplant RAS as the connection method of choice for individual remote users.

Small to Medium Solutions

Small networks are generally less volatile and more likely to use a RAS solution for incoming remote users. Typically these users are in a local calling area and use RAS in emergencies or to occasionally work from home. A VPN for a small network would probably even be counterproductive, with the overhead of ISP problems, Internet idiosyncrasies, and general VPN issues. Approaching the medium size network, the VPN has real superiority. Not only does a VPN allow individuals to connect to the organization’s private LAN, it also (as seen in Section 3.2) allows other networks to connect. Thus, as the organization expands, so does the networking solution, without a huge reinvestment of resources.

Figure 3-6 shows a medium RAS scenario and its ...