Today's corporations are challenged by the need to support a wide variety of communications across a highly distributed number of sites and offices. At the same time that the number of sites and offices increases, corporations are pressured to reduce the cost of their overall communications expenses. In addition to the increased number of office locations, employees expect to access corporate resources from a more diverse set of locations, including customer sites, home offices, and travel destinations. As more emphasis is placed on electronic communication, business partners also expect to access corporate-partner data as well. All of these trends drive the need to establish a corporate private-network infrastructure.

With regard to communications expenses, however, corporations are finding that traditional architecture does not provide the flexibility and solutions required. Using dedicated leased-line circuits to interconnect main offices and branch offices often requires significant planning time, and once in place the circuits cannot support remote or customer sites. The increase in telecommuting and remote computing is, in turn, increasing resources spent on remote-access modems, servers, and long-distance telephone charges.

Private networks that utilize the Internet backbone can significantly reduce the costs of establishing and maintaining a WAN for private-networking purposes. Internet service provider (ISP)–based private networks offer a global footprint with ubiquitous local network access. Using an ISP–based private network, corporations can connect their offices to the ISP's local points of presence (PoPs) rather than purchase costly leased-line circuits to interconnect their office locations. The corporation takes advantage of the ISP's established backbone, which is usually more geographically diverse than its WAN architecture. The ISP can also offer local dial-up access at a diverse number of locations, which helps reduce long-distance remote-access costs.