A switching system using identical switching nodes.

摘要

A switching architecture with identical switching nodes having a topology which allows for multiple paths between any two endpoint switching nodes without intervening switching nodes being involved in call control on those paths. This architecture is made feasible by a new type of link, the flexible rate interface (FRI) link. The FRI link has its own signaling channel distinct from the signaling channel of a standard link and is transparent to intervening switching nodes. Only endpoint switching nodes are aware of the existence of the FRI link with respect to call control. A standard protocol is utilized on the signaling channels of both the standard link and the FRI link. Advantageously, the standard link may be an ISDN link and the standard protocol may be the ISDN protocol. An FRI signaling channel of the FRI link may be established by using any of the following: a B channel of a standard ISDN link, standard ISDN user information transport facilities, or a logical link of a D channel of a standard ISDN link. In combination with the FRI signaling channel, the FRI link may utilize B channels from a number of standard ISDN links for FRI B channels.