Overview; What Is Frame Relay; Permanent And Switched Virtual Circuits; Data Link Connection Identifier - 3Com 3C421600A Management Manual

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Overview

What is Frame Relay?

Permanent and
Switched Virtual
Circuits
Data Link Connection
Identifier
F R
RAME ELAY
The SuperStack II Remote Access System 1500 (RAS 1500) supports a
Frame Relay interface to a wide area network (WAN). This allows for
dedicated high throughput, low error connectivity to remote locations
using public or private Frame Relay. Frame Relay technology is
standardized and supported by a variety of remote access devices
allowing the RAS 1500 to operate with remote access device from other
manufacturers.
Frame Relay is a data-link layer protocol that provides for frame/packet
switched wide area networking. It operates at the physical and data-link
layers of the OSI model, so it is transparent to the network layer. It uses
statistically multiplexed virtual circuits within a single physical bearer. Each
of the circuits can be configured to provide a guaranteed throughput and
allow for bursts of extra traffic.
Frame Relay supports "congestion management," which attempts to
notify endpoints that the network is experiencing congestion and that
the volume of traffic should be reduced to stop Frame Relay nodes from
discarding frames.
Frame Relay reduces its error-correction overhead by assuming
high-quality transmission lines and relying on the endpoints to detect and
correct transmission errors. This reduces the latency to packet throughput
within the Frame Relay network.
Frame Relay operates at speeds up to 2.048 Mbps. Typically, Frame Relay
services are provided by a public carrier such as your telephone company.
However, some organizations, such as large corporations or governments
have created private Frame Relay networks of their own.
Frame Relay uses both permanent virtual circuits (PVCs) and switched
virtual circuits (PVCs) to connect locations. The RAS 1500 currently
supports only PVCs.
Each Frame Relay frame is addressed to its destination using the Data Link
Connection Identifier (DLCI). A DLCI identifies each end of the PVC.