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"

1 - Examples

    1. The following example toggles between remote UNIX host biway
       and the local OpenVMS system.

       biway> <Ctrl/]>  (characters not echoed)
       TELNET> SHOW STATUS
       Session  1 Active  Host biway Port 23
           Operating Mode: Character-at-a-time
           Escape character: '^]'
           Options:
              Echo - Remote
              Terminal Type - Local
              Terminal Type - VT300
              Suppress Go Ahead - Local
              Suppress Go Ahead - Remote
           Terminal Dataoveruns:    0
           Suspended Network I/Os:  0

          .
          .
          . )
       TELNET> <Return>
       biway>

    2. In the next example, user BENTLEY, working at OpenVMS node
       EAGLE, uses TELNET to do the following:

       1. Establish a connection to UNIX host fern.

       2. Return to the local TELNET prompt.

       3. Display status.

       4. Establish a connection to host gannet.

       5. Return to the TELNET prompt.

       6. Display status.

       7. Connect to sands. But, sands closes the connection because
          BENTLEY incorrectly enters the password three times.

       8. Try to resume the session with gannet. However, RESUME
          without specifying a session number fails:

          -  With multiple sessions, RESUME's default is the
             "active" session, the one with the most recently opened
             connection.

          -  The most recent host to which BENTLEY connected is
             sands. However, due to BENTLEY's incorrectly typing
             of the password during login, sands closed the TELNET
             connection. Thus, TELNET displays "No current session."

          -  Because no connection is "active" (or "current"),
             BENTLEY must specify a session number on the RESUME
             command line.

       $ TELNET FERN
          .
          .
          .
       fern> <Ctrl/]>        (characters not echoed)

       TELNET> SHOW STATUS
       Session  1 Active  Host FERN
          .
          .
          .
       TELNET> CONNECT GANNET
          .
          .
          .
       gannet> <Ctrl/]> (characters not echoed)
       TELNET> SHOW STATUS
       Session  2 Active  Host GANNET
           Operating Mode: Character-at-a-time
           Escape character: '^]'
          .
          .
          .
       Session  1 Waiting Host FERN

       TELNET> CONNECT SANDS
       %TELNET-I-Trying, Trying...11.18.222.95
       %TELNET-I-SESSION, Session 03, host sands, port 23
       -TELNET-I-Escape, Escape character is '^]'.
          .
          .
          .
             Sun Microsystems, Inc. UNIX System sands - Authorized Access Only

       Username: BENTLEY
       Password:
       User authorization failure
       Username: BENTLEY
       Password:
       User authorization failure
       Username: BENTLEY
       Password:
       User authorization failure

       Remote connection closed

       TELNET> RESUME
       No current session
       TELNET> SHOW STATUS

       Session  1 Waiting Host FERN
       Session  2 Waiting Host GANNET
          .
          .
          .
       TELNET> RESUME 2

       gannet> <Ctrl/]>          (characters not echoed)
       TELNET> SHOW STATUS
       Session  2 Active  Host GANNET
           Operating Mode: Character-at-a-time
           Escape character: '^]'
          .
          .
          .
       Session  1 Waiting Host FERN
       TELNET>