Frame relay is a packet-switching telecommunication service designed for cost-efficient data transmission for intermittent traffic between local area networks (LANs) and between endpoints in wide area networks (WANs). The service, once widely available and implemented, is in the process of being discontinued by major Internet service providers. Sprint ended its frame relay service in 2007, while Verizon said it plans to phase out the service in 2015. AT&T stopped offering frame relay in 2012 but said it would support existing customers until 2016.

1. FRAME RELAY
Department of Electrical Engineering
Bahria University Islamabad campus

2. OBJECTIVES
• Introduction
• Drawbacks of x.25 and leasing t-1 or
t-3 lines
• Features of frame relay
• Architecture
• FR layers
• FR frame
• DTE (Data Terminal Equipment)

3. OBJECTIVES
• DCE (Data Communications
Equipment)
• FR Terminology
• FR topologies
• Conclusion

4. INTRODUCTION
• Frame relay is a VC wide-area network that was designed in
response to demands for a new type of wan in the late 1980s
and early 1990s.
• It operates at the data link layer of the OSI reference model.
• Frame Relay uses a subset of the high-level data link control
(HDLC) protocol called Link Access Procedure for Frame Relay
(LAPF).
• Frames carry data between user devices called data terminal
equipment (DTE), and the data communications equipment
(DCE) at the edge of the WAN.

5. Drawbacks of X.25
• X.25 has a low 64-kbps data rates.
• Flow and error control at both layers
create a large overhead and slow down transmission
• Originally X.25 was designed for private use, not for
internet.

6. Drawbacks of T1or T3 lines
• Very costly
• T1 and t3 lines has fixed rate data all the
time, but the user needs different
bandwidth allocations at different times.

7. Features of FR
• FR operates at higher speed.
(1.544 Mbps and recently 44.376).
• FR operates in just the physical and data link layers.
• FR allows bursty data.
• FR allows a frame size of 9000 bytes.
• Less expensive.
• There is no flow control and error control.

8. ARCHITECTURE

9. FR LAYERS

10. FR FRAME

11. DTE (Data terminal equipment)
• DTEs generally are considered to be terminating
equipment for a specific network and typically are
located on the premises of the customer.
• The customer may also own this equipment.
• Examples of DTE devices are routers and Frame
Relay Access Devices (FRADs).

12. DCE (Data connecting equipment)
• DCEs are carrier-owned internetworking devices.
• The purpose of DCE equipment is to provide clocking
and switching services in a network.
• In most cases, these are packet switches, which are
the devices that actually transmit data through the
WAN.

13. FR Terminology
SVC PVC
• Switched Virtual Circuits (SVCs) are Virtual circuits may be
established dynamically by sending signaling messages to the
network.
• However, SVCs are not very common.
• Permanent Virtual Circuits (PVCs) are more common.
• PVC are VCs that have been preconfigured by the carrier are
used.
• The switching information for a VC is stored in the memory of
the switch

14. Conclusion
• Frame relay protocol is a simplified X.25
WAN protocol. It is a kind of statistical
multiplexing protocol that can establish
multiple virtual circuits (VC) over a single
physical cable.
• A frame relay network can be a public
network, a private enterprise network, or a
network formed by direct connections
between data devices.