You can use the OpenVMS Phone utility (PHONE) to communicate with
    other users on your system or with any other system connected to
    your system by DECnet for OpenVMS. Phone is designed to simulate
    some of the features of actual telephone communications, such as
    the hold button, conference call, and telephone directories.

    To invoke the Phone utility, enter the PHONE command at the DCL
    prompt and press Return. You can specify the user name of the
    person with whom you want to communicate before or after you
    enter the Phone utility. When you invoke the Phone utility, Phone
    displays the Phone screen layout, known as the viewport.