1-17 system all the elements that make up the naval communications system and the Army and Air Force equivalent. The switched networks discussed in this section, automatic voice network, automatic secure voice communications, automatic digital network, and the defense special security communications system, are part of the DCS and are managed by the Defense Communications Agency (DCA). You should not confuse these DCS networks with the HICOM (high-command communications network) and NORATS (Navy operational radio and telephone switchboard) networks. We will discuss both of these Navy-only networks later in this chapter. Automatic Voice Network (AUTOVON) The DCS AUTOVON offers rapid, direct interconnection of DOD and certain other government installations through worldwide telephone exchanges. AUTOVON is a worldwide, general-purpose direct dialing telephone system. The goal of the AUTOVON system is to complete connections between two points anywhere in the world in about two seconds and to complete regular connections with push-button speed. The AUTOVON system is made up of several installations comparable in function to commercial telephone exchanges. An installation is referred to as an AUTOVON switch, or simply switch. Within individual areas we have local command, control, and administrative voice communications systems. These systems connect into the worldwide AUTOVON through manually operated telephone switchboards or automatic dial exchanges by using direct in and out dialing. Normal AUTOVON service allows your station to call other stations on a worldwide basis for day- to-day communications by using the telephone. Automatic Secure Voice Communications (AUTOSEVOCOM) Another close relative to the AUTOVON system is the AUTOSEVOCOM a worldwide, switched telephone network. It provides authorized users with a means for exchanging classified information over communications security (COMSEC) circuitry or over other approved circuitry. The system consists of both manual and automated networks within a single system. For subscribers to the AUTOSEVOCOM network, telephone directories containing subscriber listings, general instructions for placing calls, and trouble-reporting procedures are provided. Automatic Digital Network (AUTODIN) The DCS AUTODIN is a fully automatic, digital system. The system converts word messages to digital form for transmission. AUTODIN is used to furnish instantaneous, error-free, and secure communications around the world to several thousand directly connected subscriber terminals. Daily capacity of the system is about five- million average-length messages. AUTODIN switching centers are interconnected through a network of high-frequency radio channels, submarine cables, microwave and tropospheric channels, and a variety of wire lines. The whole concept of AUTODIN is to reduce manual handling of messages to a minimum by the use of automated equipment. This system has reduced message delivery times and delay anywhere in the world to a matter of seconds rather than minutes or hours.