What is Frame Relay?

When you send and receive information on the Internet by viewing a web page, sending an e-mail, or downloading a file, you are making use of a network protocol that governs how networks interact with each other. Frame Relay is an older protocol that is still used in many rural areas where high speed internet connections are not available and by some organizations that have not upgraded to newer services.

History

In the earliest years of the development of the internet a group called the Telecommunication Standardization Sector in Switzerland developed a network protocol called "X25" that defined how data should be sent and received between computers. The Frame Relay protocol was developed nearly 20 years later as a faster means of sending information by dropping many of the features of X25 that slowed down the transmission of data.

Function

The Frame Relay protocol works at the first and second layers of the Open Systems Interconnection basic reference model and connects local area networks to large internet backbones. It is normally used over a T-1 Internet line by an internet service provider or a large business that needs a dedicated network connection. The protocol breaks down data that needs to be transmitted into smaller pieces called frames that consist of a header that identifies the data followed by the actual data itself. Error checking information is not included in the frame's header to keep the size manageable.

Features

Each frame that is transmitted between computers consists of several different fields. The flag field lets the destination computer know where the frame starts and where it will end. The address field notifies the destination of where the frame came from and then the information field states how large the frame will be. The final field is composed of the actual chunk of data.

Considerations

You may experience unexpected speed slowdowns or infrequent instances of receiving garbled information over the Internet when using the Frame Relay protocol. It attempts to send frames as quickly as possible so it does not attempt to prevent collisions or errors. When errors are discovered the protocol tells the computer to drop the frame altogether and then resend it.

Potential

The Frame Relay protocol was designed when dial-up services where the fastest connection available so it lacks many of the features that newer protocols use to take advantage of the speed gains of cable and DSL Internet connections. It is highly likely that Frame Relay will no longer be used by most Internet service providers as dial-up Internet connections lose popularity.

Resources

• Cisco Frame Relay Resources