With the advent of broadband services such as DSL and cable modem, Ethernet WAN (point-to-point Ethernet service over fiber optic cable), VPN, and Multiprotocol Label Switching (MPLS), Frame Relay has become a less suitable solution for accessing the WAN. However, there are still locations in the world which rely on Frame Relay for connectivity to the WAN.
Frame Relay provides greater bandwidth, reliability, and resiliency than private or leased lines.
Using an example of a large enterprise network helps illustrate the benefits of using a Frame Relay WAN. In the example shown in the figure, SPAN Engineering Company has five campuses across North America. Like most organizations, SPAN’s bandwidth requirements are varied.
The first thing to consider is the bandwidth requirement of each site. Working from the headquarters, the Chicago-to-New York connection requires a maximum speed of 256 kb/s. Three other sites need a maximum speed of 48 kb/s connecting to the headquarters, while the connection between the New York and Dallas branch offices requires only 12 kb/s.
Before Frame Relay became available, SPAN Engineering Company leased dedicated lines.
Note: The bandwidth values used in the leased line and Frame Relay examples throughout this chapter do not necessarily reflect current bandwidths used by many customers today. The bandwidth values used in this chapter are only for comparison purposes.