The separate components of a company's telecommunications system, and any service provider that works with them, all pose distinct security risks. Specialized solutions should be designed to ensure the security of: (1) the private branch exchange, a telephone switching mechanism that connects a company's telephones and modems to the public telephone network; (2) an integrated switched digital network, very small aperture terminal or frame relay, which carry data communications; (3) procedures that involve human operators; and (4) modems. The article describes specific security risks connected with individual components, and suggests procedures to minimize the risks. In addition to protecting company information with technological improvements, ancillary solutions such as data encryption and constant transmission monitoring can help ensure data integrity.