A virtual circuit (VC) is a means of transporting data over a packet-switched network in such a way that it appears as though there is a dedicated physical link between the source and destination end systems of this data. The term virtual circuit is synonymous with virtual connection.

<networking> 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. (2001-10-26)

<networking> (PVC, or in ATM terminology, "Permanent Virtual Connection") A virtual circuit that is permanently established, saving the time associated with circuit establishment and tear-down. (1997-10-06)

virtual circuit

<networking> 1. (VC) A connection or a path through an ATM network. The word "virtual" indicates that the connection is logical rather than physical. Nothing to do with a virtual circuit on a packet switching network. [Fred Halsall, "Data Communications, Computer Networks and Open Systems", 1996, Addison Wesley]. 2. A communications link that appears to be a direct connection between sender and receiver, although physically the link can be routed through a more circuitous path, running over virtual circuits instead of a private network built primarily with dedicated lines. A virtual connection can provide full-time connection among many sites, including those configured for SNA/SDLC protocol. A virtual connection can handle any transmission protocol and is supported worldwide. It can provide high throughput and low delay for LAN and Internet applications, peer-to-peer connectivity, client-server computing, and other distributed processing applications. [Same as virtual circuit?] (2001-10-26)

Virtual circuit multiplexing or VC-MUX is one of the two (the other being LLC encapsulation) mechanisms for identifying the protocol carried in ATM Adaptation Layer 5 (AAL5) frames specified by , Multiprotocol Encapsulation over ATM.

Virtual hosting is a method for hosting multiple domain names (with separate handling of each name) on a single server (or pool of servers). This allows one server to share its resources, such as memory and processor cycles, without requiring all services provided to use the same host name.

circuit switching

<communications> Communication via a single dedicated path between the sender and receiver. The telephone system is an example of a circuit switched network. The term connection-oriented is used in packet-based networks in contrast to connectionless communication or packet switching. (2006-09-20)

Circuit switching is a method of implementing a telecommunications network in which two network nodes establish a dedicated communications channel (circuit) through the network before the nodes may communicate. The circuit guarantees the full bandwidth of the channel and remains connected for the duration of the communication session.