Frame Relay - 5 : Overview

Frame relay is a wide area networking technology designed to fit between the capabilities of leased lines and ISDN. The official definition of frame relay is "a shared, packet-switched, connectionless, permanent connection designed to support data services." However, there has been some use of frame relay in providing voice services.

As we discussed in an earlier lesson, packet switched networks share bandwidth across a service provider's switched network. All traffic is packetized and addressed, just as it is on an Ethernet network, and inserted into the flow of traffic. Frame relay is connectionless, so data can just be sent when it's ready and does not have to wait for a connection to be established. The connection is considered permanent because the corporate customer has a permanent connection into the switched network.

The biggest advantage of frame relay is cost. Instead of having to pay for dedicated leased lines to connect each remote site, frame relay provides a much less expensive shared service. Unfortunately, frame relay's greatest advantage is also its greatest disadvantage. Sharing bandwidth, though it reduces cost, can also result in delay. Because of this, it is important for network managers to determine what their needs are before choosing frame relay over another WAN service.

If an organization has a high volume of critical communication between sites, leased lines might be the best way to go.

If there is a low volume of communication that occurs at irregular intervals, dial-up ISDN may be the appropriate WAN technology to use.

And finally, if there are many sites frequently exchanging data information, then frame relay may be the best choice.

Also remember, you can mix and match these technologies. Some sites may need leased lines, some may need ISDN, and some may be better off with frame relay.