Appendix B Virtual Circuit Topology; Diagram 1 Virtual Circuit Topology - ZyXEL Communications Prestige 630-C series User Manual

ATM is a connection-oriented technology, meaning that it sets up virtual circuits over which end systems
communicate. The terminology for virtual circuits is as follows:
•
Virtual Channel
•
Virtual Path
•
Virtual Circuit
Think of a virtual path as a cable that contains a bundle of wires. The cable connects two points and wires
within the cable provide individual circuits between the two points. In an ATM cell header, a VPI (Virtual
Path Identifier) identifies a link formed by a virtual path; a VCI (Virtual Channel Identifier) identifies a
channel within a virtual path.
The VPI and VCI identify a virtual path, that is, termination points between ATM switches. A series of
virtual paths make up a virtual circuit.
Your service provider should supply you with VPI/VCI numbers.
Virtual Circuit Topology
Virtual Circuit Topology
Logical connections between ATM switches
A bundle of virtual channels
A series of virtual paths between circuit end points

Diagram 1 Virtual Circuit Topology

Prestige 630-C Series ADSL USB Modem
Appendix B
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