ISDN ADJUNCT SWITCH FOR EXISTING CENTRAL OFFICES AND NEAX61 ISDN DIGITAL SWITCHING SYSTEM

摘要

The adjunct switch is considered for introduction in areas where users, belonging to host exchanges (Central Offices) not immediately scheduled for digitalization, are requesting ISDN services. This paper describes the structure of the ISDN adjunct system which provides ISDN services for existing analog telephone exchanges (SxS, XB, SPC). It is also shown that the system is designed to cope with future replacement of the host system by a digital switching system. The adjunct system can interwork with any type of digital switching system, since the interface with the digital host system can be a standard trunk interface. In the case that the host system is the NEAX61 ISDN system, the ISDN adjunct system can be converted to a remote switching unit, or to an independent NEAX61 Switching System with ISDN capabilities.