X.25 is a packet switched data network protocol that defines an international recommendation for the exchange of data between a user device (DTE) and a network node (DCE). Virtual circuit is the end-to-end connection (through a network) between two user devices (DTEs). Frame relay is a packet switching technology that relies on low-error-rate digital transmission links and high-performance processors. X.25 was designed to provide error-free delivery using high-error-rate links. Frame relay takes advantage of the new, lower-error-rate links, enabling it to eliminate many of the services provided by X.25. Congestion control is about controlling traffic entry into telecommunication networks. Voice over frame relay (VoFR) technology consolidates voice and voiceband data (e.g., fax and analog modems) with data services over the frame relay network. The most popular frame relay application provides companies with LAN-LAN internetworking. In addition, frame relay finds applications in voice over frame relay (VoFR), business, education, medical care, and industry.

Chapter Contents:

• 4.1 X.25 Technology
• 4.1.1 X.25 Devices
• 4.1.2 X.25 Virtual Circuits
• 4.1.3 X.25 Protocol Suite
• 4.1.4 Benefits and Drawbacks of X.25
• 4.2 Frame Relay
• 4.2.1 Frame Relay Technology
• 4.2.2 Frame Relay Protocol Data Unit
• 4.2.3 Virtual Circuit Size Parameters
• 4.2.4 Major Advantages and Disadvantages
• 4.3 Frame Relay Standards
• 4.4 Frame Relay Versus X.25
• 4.5 Voice Over Frame Relay
• 4.6 Congestion Control
• 4.7 Frame Relay Applications
• Summary
• Review Questions
• Problems

Inspec keywords: packet switching; local area networks; telecommunication congestion control; relay networks (telecommunication); LAN interconnection; frame relay; telecommunication links; protocols; Internet telephony; telecommunication services; error statistics

Other keywords: network node; voice over frame relay technology; X.25; high-error-rate links; user device; telecommunication networks; end-to-end connection; DCE; virtual circuit; data services; frame relay application; low-error-rate digital transmission links; frame relay; error-free delivery; international recommendation; lower-error-rate links; voice-band data; high-performance processors; packet switched data network protocol; traffic congestion control; VoFR technology; DTE; LAN-LAN internetworking

Subjects: Other topics in statistics; Protocols; Computer communications; Protocols; Control applications in data transmission; Communication switching; Other topics in statistics; Local area networks; Telephony