Methods and apparatus for implementing switched virtual connections

Abstract

Methods and apparatus are set forth for quickly making switched virtual connections (SVCs) in a digital circuit switch that integrates voice and data using common switch, control and distribution equipment. SVCs provide concurrent data connection service from one station device, such as a PC, to other station devices over a single line for each station device where the line may also carry voice and terminal data service. A switch control processor remembers connection requests from station devices and acts on opportunities to utilize available bandwidth in an optimal manner. Dynamic connection reconfiguration techniques allow the system to 'scavenge' bandwidth unused by voice or terminal data traffic for SVCs thereby providing the largest possible data rate at any given time. Short signalling messages and indexed values are used in order to speed activation time for previously defined connections while resource allocation is performed by the switch control processor to further enhance system operating speed. The system features (a) reduced connection set up time compared with prior art circuit switch communications systems that need to establish a call each time frames are exchanged; (b) the elimination of expensive concentrators (for example, packet switches); (c) a broadcast channel; (d) enhanced traffic analysis capabilities; and (e) the communication security inherent in circuit switch architectures.