ADTRAN 1200350L1 - Manual (Page 62)

Chapter 4: Configuration Overview
4-26 Router Option Module User Manual 61200350L1-1
Frame Relay
(also available via Front Panel)
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 connec-
tion.
There are two types of virtual circuits supported in Frame Relay:
The Router Option Module supports PVCs only.
The Data Link Connection Identifier (DLCI) number identifies each
virtual circuit within a shared physical channel.
Virtual Circuit Types Description
Permanent Virtual Circuits
(PVC) PVCs are like dedicated 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 car-
rier via a network management sys-
tem.
Virtually all Frame Relay communica-
tion is done using PVCs.
Switched Virtual Circuit
(SVC) SVCs require setup and tear down and
are generally not available from Frame
Relay carriers.