In telecommunications and computer networks, a virtual circuit (VC), synonymous with virtual connection and virtual channel, is a connection oriented communication service that is delivered by means of packet mode communication. After a connection or virtual circuit is established between two nodes or application processes, a bit stream or byte stream may be delivered between the nodes; a virtual circuit protocol allows higher level protocols to avoid dealing with the division of data into segments, packets, or frames.
Virtual circuit communication resembles circuit switching, since both are connection oriented, meaning that in both cases data is delivered in correct order, and signalling overhead is required during a connection establishment phase. However, circuit switching provides constant bit rate and latency, while these may vary in a virtual circuit service due to factors such as:
- varying packet queue lengths in the network nodes,
- varying bit rate generated by the application,
- varying load from other users sharing the same network resources by means of statistical multiplexing, etc.
Many virtual circuit protocols, but not all, provide reliable communication service, by means of data retransmissions because of error detection and automatic repeat request (ARQ).
An alternate network configuration to Virtual circuit is Datagram.
Read more about Virtual Circuit: Layer 4 Virtual Circuits, Layer 2/3 Virtual Circuits, Examples of Protocols That Provide Virtual Circuits, Permanent and Switched Virtual Circuits in ATM, Frame Relay, and X.25
... This means that either the two hosts at the ends of a virtual circuit must agree a priori that the circuit will be used for one specific protocol (e.g ... the circuit will only be used to send IP datagrams), or the two hosts at the ends of a virtual circuit must agree a priori that some octets of the data area will be reserved for use as a ... The former scheme, in which the hosts agree on the high-level protocol for a given circuit, is referred to in RFC 2684 as "VC Multiplexing" ...
... Switched virtual circuits (SVCs) are generally set up on a per-call basis and are disconnected when the call is terminated however, a permanent virtual circuit (PVC) can be established as an option to ... A switched virtual circuit (SVC) is a virtual circuit that is dynamically established on demand and is torn down when transmission is complete, for example after a phone call or a file download ... A permanent virtual circuit (PVC) is a virtual circuit established for repeated/continuous use between the same DTE ...
... Circuit mode communication, for example the public switched telephone network, ISDN, SONET/SDH and optical mesh networks, are examples of connection-oriented ... Circuit mode communication provides guarantees that data will arrive with constant bandwidth and at constant delay ... also be connection-oriented, which is called virtual circuit mode communication ...
... One issue, whether sidewalks were covered by the ADA, was appealed to the 9th Circuit Court of Appeals, which ruled that sidewalks were a "program" under ADA and must be made accessible to persons with disabilities ... the case, letting stand the ruling of the 9th Circuit Court ... was accepted by a federal court in Florida and, subsequently, the Fifth Circuit Court of Appeals ...
2684 describes two encapsulation mechanisms for network traffic Virtual and DSL modems often include a setting for RFC 1483 bridging ... In VC Multiplexing (VC-MUX), the hosts agree on the high-level protocol for a given circuit ... The chief disadvantage of such a scheme lies in duplication of virtual circuits a host must create a separate virtual circuit for each high-level protocol if more ...
Famous quotes containing the words circuit and/or virtual:
“We are all hostages, and we are all terrorists. This circuit has replaced that other one of masters and slaves, the dominating and the dominated, the exploiters and the exploited.... It is worse than the one it replaces, but at least it liberates us from liberal nostalgia and the ruses of history.”
—Jean Baudrillard (b. 1929)
“Tragedy dramatizes human life as potentiality and fulfillment. Its virtual future, or Destiny, is therefore quite different from that created in comedy. Comic Destiny is Fortunewhat the world will bring, and the man will take or miss, encounter or escape; tragic Destiny is what the man brings, and the world will demand of him. That is his Fate.”
—Susanne K. Langer (18951985)