BISDN Configuration: Fig. shows how access to the BISDN network is accomplished. Each peripheral device is interfaced to the access node of a BISDN network through a broadband distant terminal (BDT). The BDT is responsible for electrical to optical conversion, multiplexing of peripherals, and maintenance of the subscriber’s local system. Excess nodes concentrate several BDT’s into high speed optical fiber line directed through a feeder point into a service node. Most of the control function for system excess is managed by the service node, such as call processing, administrative function and switching and maintenance functions. The functional modules are interconnected in a star configuration and include switching, administrative, gateway, and maintenance modules. The interconnection of the function module is shown in Fig. The central control hub acts as the end user interface for control signaling and data traffic maintenance. In essence, it oversees the operation of the modules.
Subscriber terminal near the control office may by pass the excess nodes entirely and the directly connected to the BISDN network through a service node. BISDN nodes that used optical fiber cables can utilize much wider band width and consequently, have higher transmission rates and offer more channel handling capacity than ISDN systems.