VMS Help TCPIP Services, TELNET, Toggling  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    During a session with a remote host, you can toggle back and
    forth between the local TELNET or TN3270 process and the
    connected host. For example, at the TELNET prompt, you might
    want to display status, modify a TELNET parameter, or spawn a DCL
    subprocess.

    o  To return to the local TELNET or TN3270 prompt (TELNET command
       mode), enter the TELNET escape sequence (the default is
       Ctrl/]) at the remote host's prompt (TELNET input mode).

    o  To resume your session with the remote host, enter one of the
       following at the TELNET (or TN3270) prompt.

       TELNET> <Return>

       or

       TELNET> RESUME

       or

       TELNET> RESUME n

       where n is the number of the session to which you want to
       return.

    o  To change the default escape sequence, enter the following at
       the TELNET (or TN3270) prompt:

       TELNET> SET ESCAPE "^escape_character"

  Additional Information (explode) :

• Examples