The DMS-100 Switch is one of a line of Digital Multiplex System (DMS) telephony switches manufactured by Nortel Networks.
The purpose of the DMS-100 Switch is to provide local telephone service and connections to the public telephone network. It is designed to deliver services over subscribers lines and trunks. It provides POTS (Plain Old Telephone Service), along with very sophisticated business services such as ACD (Automatic Call Distribution), ISDN (Integrated Service Digital Network), and MDC (Meridian Digital Centrex).