Resumes an open TELNET or TN3270 session that you interrupted
    with the escape sequence. When you run simultaneous multiple
    sessions (TELNET only):

    o  To resume a particular session, specify a session number.

    o  To resume the active session, omit the session number.

    o  If no session is active, you must specify a session number.

                                      NOTE

          TELNET interprets the active session as the last session
          with which you communicated. If that communication
          ended with you logging out, you have no active sessions.
          However, you might have other waiting (alive) sessions.

    DCL Format

      RESUME  [ session_number ] <Return>

    UNIX Format

      <Return>