IT support businesses sell all types of computer services and products. (For a list of popular computer services a typical IT support business provides, see this article and graphic.) Computer Network Support is one of many computer services offered by an IT support company. Computer Network Support involves the installation, coordination, troubleshooting, and maintenance of internal networks. Computer Network Support also involves the use of peripheral devices, such as modems, routers, scanners, fax machines, and telephone networks. Computer Network Support involves the installation of internal telephones.