Abstract

A real time fault tolerant transaction processing system, particularly one suited for use in a service control point (SCP), is described. Specifically, the system utilizes a communication protocol, such as signalling system 7, that adaptively distributes message packets on an equal basis over multiple physical links that connect two points, such as an SCP and a signalling transfer point (STP), and non-fault tolerant front end and back end processors that are connected to each physical link for processing packets appearing on that link and providing corresponding responses thereto. All the front and back end processors are loosely coupled together for purposes of processor synchronization and re-assignment. Through this system, all the physical links simultaneously carry an equal number of packets which are, in turn, processed by all the processors connected thereto. In the event any physical link or either a front or back end processor connected thereto fails, then that link is declared to be out of service. Consequently, the protocol merely re-assigns all subsequently occurring packets to the other links until such time as the fault is cleared. As the result of link re-assignment, there is advantageously no need to connect a fault tolerant processor to each physical link. This, in turn, substantially and advantageously reduces the complexity and cost of the fault tolerant transaction processing system.

Other References

• Bell Communication Research Specification of Signalling System 7, Tech Ref. TR-NPL-000246, Issue 1, vol. 1, 1985, Bell Communication Research
• "Get Inside CCITT Signalling System No. 7", Telephony, 3/10/86, pp. 72-77, M. G. Walker
• "Service Control Point--Database For 800 Service", written by Boese and Hood, Bell Communication Researc