Intercom systems are widely deployed and used in numerous types of facilities around the world ranging from residential to commercial to high security military facilities. It is the communications system that offers optimal security for people, goods and valuables. The communications system also enhances safety and provides an added sense of security.

Intercom systems are comprised of communication servers and communication stations. Communication servers are modular and support various communication protocols and transmission methods. Data communication between servers is typically Ethernet-based. Communication stations support either the standard TCP/IP protocol or the manufacturer's proprietary serial protocol. The former requires a standard Ethernet twisted pair cable connected to network switch, while the latter may use either a 2 or 4 conductor cable, and are wired directly to the communication server. Communications stations are categorized as master or slave (substation). Master stations are installed in the command and control center while the substations are installed at remote locations. The main distinction is the functionality of the station.

A typical substation has a single push button to initiate the voice communication. Master stations have a numeric keypad and multiple function keys to perform several different functions with more than one connected substation. Voice communication is normally initiated at the substation. When the push button at the substation is pressed, it opens a voice channel with to a pre-determined master station. This voice channel can be forwarded to a different master station if the designated master station fails to answer the call within a predefined duration.