No. 10A Remote Switching System: System Overview

This paper is an overview of the No. 10A Remote Switching System (10A RSS), including some background, results of earlier planning studies, system objectives, and information on the major hardware and software elements of the system. Companion papers in this issue of The Bell System Technical Journal will discuss some of these elements in greater detail. The major components of the 10A RSS include a host Electronic Switching System (ESS), one or more 10A RSS frames and data links for communication between the host and remote site(s). Figure 1 details this arrangement. At this time, the host function has been developed for the Western Electric No. 1 ESS machines, and work is now in progress to develop the host capability for the Western Electric No. 1A and No. 2B ESS machines. The data link used for the No. 1/1A E S S - R S S communication function is a new design utilizing an intelligent peripheral unit controller (PUC-DL) which can interface with up to 16 data links. The 10A RSS data link communication makes use of the X.25 protocol. The 10A RSS basic frame can serve up to 1024 lines. A companion frame may be added to allow up to 2048 lines to be served by a single RSS entity. The design is such that the basic element of 391