TABS - an Asynchronous Block Serial Protocol for Multipoint Applications

Abstract

Since the early 1960’s, AT&T has established a trend toward centralized and remote operations of the transmission network. Thorough and continuous monitoring of global network properties can only be achieved through centralization. As a result, a secondary network has evolved in support of these monitoring functions. The “telemetry network” comprises a system of distributed processors dedicated to analyses of the transmission network, together with all necessary communication links. Monitoring access to the transmission network is provided at special interface points. Often the interface hardware is integrated into the transmission network element itself. AT&T uses a special protocol, TABS, the Telemetry Asynchronous Block Serial protocol, at the interface between the telemetry network and the transmission network.[1] TABS was designed by AT&T Bell Laboratories to optimize the performance and economics of this interface. In this paper, we describe the structure of that protocol, its performance properties and current implementations.