ADTRAN L768 - Manual (Page 64)

Chapter 3: Terminal Menu Operation and Structure
48 Express L768/L1.5 User Manual 61202192L1-1
Configuration/Frame Relay
Frame Relay is a connection-oriented service requiring circuits to be config-
ured by your carrier to establish a physical link between two or more locations.
Multiple virtual circuits (which appear as virtual point-to-point links) can be
run through the same physical connection.
There are two types of virtual circuits supported in Frame Relay: Permanent
Virtual Circuits (PVC) and Switched Virtual Circuit (SVC). PVCs are like ded-
icated point-to-point private lines. Since the physical connection is always
there in the form of a leased line, call setup and tear down is done by a carrier
via a network management system. SVCs require setup and tear down and are
generally not available from Frame Relay carriers. Virtually all Frame Relay
communications is done using PVCs. The Express L768/L1.5 supports PVCs
only.
A number called the Data Link Connection Identifier (DLCI) identifies each
virtual circuit within a shared physical channel.
Figure 3-8 shows the Frame Relay menu.
Figure 3-8
Configuration/Frame Relay Screen