ADTRAN Express L768 - Manual (Page 70)

Chapter 3. Terminal Menu Operation and Structure
3-36 Express L768 User Manual 61203192L1-20
» Configuration/Frame Relay
Frame Relay is a connection-oriented service requiring circuits to be
configured 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: Per-
manent Virtual Circuits (PVC) and Switched Virtual Circuit (SVC).
PVCs are like dedicated point-to-point private lines. Since the physi-
cal 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 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