virtual circuit

virtual circuit

(1) A temporary communications path created between devices in a switched communications system. For example, a message from New York to Los Angeles may actually be routed through Atlanta and St. Louis. Within a smaller geography, such as a building or campus, the virtual circuit traverses some number of switches, hubs and other network devices.

(2) A logical circuit within a physical network. The actual lines may be shared by other users at the same time, but the virtual circuit appears exclusive to the users who are communicating with each other. The terms "permanent virtual circuit" and "virtual private network" also describe this kind of logical circuit. See packet switching, VPN, PVC and SVC.

---

(networking)

virtual circuit - A connection-oriented network service which is implemented on top of a network which may be either connection-oriented or connectionless (packet switching). The term "switched virtual circuit" was coined needlessly to distinguish an ordinary virtual circuit from a permanent virtual circuit. (One of the perpetrators of this confusion appears to be ["Networking Essentials", 1996, Microsoft Press, ISBN 1-55615-806-8], a book aimed at people preparing for the MCSE exam on LANs and WANs). Not to be confused with switched virtual connection.