ATM and Frame Relay SVCs, and SPVCs 8-3
ATM and Frame Relay SVCs and SPVCs
Refer to the Cisco WAN Service Node Extended Services Processor Installation and Operation for
Release 2.2 document for detailed information about SPVCs.
SVCs
A switched virtual circuit (SVC) only exists when there is data to send and a calling process has been
initiated. With a switched virtual circuit, there must be some signaling mechanism to build a
connection each time the user (ATM or Frame Relay device in this case) needs it. In addition, when
the call is disconnected, there must be a mechanism for the orderly disconnection of the call, and the
network’s resources must be relinquished. During a disconnect, the Cisco StrataCom network
sweeps through its connection tables and removes the connection.
ATM SVCs are ATM connections setup and maintained by a standardized signaling mechanism
between ATM CPE (ATM user end systems) across a Cisco StrataCom network. ATM SVCs are
created on user demand and removed when the call is over, thus freeing up network resources.
Frame Relay SVCs are Frame Relay connections setup and maintained by a standardized signaling
mechanism between Frame Relay CPE (Frame Relay user end systems) across a Cisco StrataCom
network. Frame Relays SVCs are created on user demand and removed when the call is over, thus
freeing up network resources.
