Toll and assistance and listing services are two important applications of the operator services position system (OSPS). These applications are built on the distributed architecture of the 5ESS® switch and use the building blocks provided by the OSPS software architecture to incorporate new features easily. This article focuses on two toll and assistance features, interflow and more efficient call handling (MECH), as well as the listing services application and a combination of the two applications through the combined services feature to demonstrate the power of the OSPS software architecture.

The Traffic Service Position System No. 1B (TSPS No. 1B) was developed by replacing the Stored Program Control No. 1A (SPC 1A) with the SPC 1B, consisting of a 3B20 Duplex Processor (3B20D) and a Peripheral System Interface (PSI). The PSI was designed to interface the 3B20D Processor technology with the existing TSPS peripheral system. This article describes the differences in technologies between the SPC 1A and SPC 1B, the hardware design required to overcome these differences, and the fault recovery and diagnostic software development required to integrate the new hardware into the maintenance structure of the TSPS No. 1B.