Stored Program Controlled Network: Routing of Direct-Signaling Messages in the CCIS Network
R. F. Frerking, M. A. McGrew · Bell System Technical Journal · 1982
This paper compares and contrasts the two methods currently used to route messages through the common-channel interoffice signaling (CCIS) network. Since its introduction in 1976, the CCIS network has been providing routing of telephone signaling messages between switching offices using permanent virtual circuits. In 1980, a new datagram routing capability, called direct signaling, has been added that significantly enhances the network's ability to interconnect Stored Program Control (SPC) systems. Stored program control systems interconnected by the signaling network can now communicate in support of improved SPC network services in addition to CCIS trunk-related call-control signaling. This paper briefly reviews banded telephone routing and then describes and compares direct signaling routing. The new flow control procedures required to implement direct signaling are discussed and two examples of applications using direct signaling are presented.