A connection-orientednetwork 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)