In addition to the million or more such hosts, many millions of computers are directly attached through private local networks (eg, in offices) using various protocols, and untold millions dial into hosts via ordinary telephone lines. If the protocol of the private network or dial-in call is TCP/IP and appropriate software is installed on the user computer (notably a form of SLIP or else PPP for dialed-up connections), then the user is regarded as being directly on the Internet and has access to all facilities. Host computers are owned and operated by universities, corporations and government agencies and for the general public by co-operatives and specialty commercial companies; in this role of providing Internet access, each of these organizations is referred to as an "Internet Service Provider" (ISP).