Conference irocz::terminal_servers

3505.0. "MUXserver Reverse-TELNET Connections" by CSC32::L_DEGROFF () Thu Apr 17 1997 17:52

    Have customer with many MUXServer 380s configured as show in the
    sample below:
                       Thickwire Backbone
    -------------------------------------------------------------
                                  |
                                MS380
                ------------------|------------------
                |                 |                  |
          DECmux 300 (C1)   DECmux 300 (B1)     DECmux 300 (A1)
                                  |                  |
                            DECmux 300 (B2)     DECmux 300 (A2)
                                  |
                            DECmux 300 (B3)
    
    The MS380 is an IP capable MUXserver.  The DECmux 300 supports
    the creation of TELNET LISTENER ports.  According to the Manage-
    ment manual, the range of TELNET LISTENER ports is 23, and 2001
    thru 2016.  However since the TELNET LISTENER port is created on
    the DECmux, the actual limitation is the physical number of ports
    on the DECmux, i.e. an 8-port DECMux will not accept TELNET 
    LISTENER port 2009.  This has been verified in our lab.  
    
    To solve a network problem related to the use of LAT as the protocol
    for printer ports, we have recommended that the customer switch 
    from LAT to TELNET.  The customer uses a large number of the DECmux
    ports connected to each MUXserver for this purpose and so, will
    require a large number of TELNET LISTENER ports.  In some cases,
    almost one for each DECmux port for each DECmux connected to a
    MUXserver.
    
    From the management manual, we can setup a TELNET LISTENER on each
    port of each of the DM300-16 servers.  We did so on one in the lab
    and on the MUXserver, a SHOW TELNET LISTENER ALL did, in fact, show
    TELNET LISTENER port 23 and the port 2007 that we created on STATION
    A1.  However, since a TELNET connection is made using the IP address
    of the MUXserver and a TCP port_number of a DECmux, in this case
    2007, it would appear that the TELNET LISTENER port 2007 cannot be
    used again for any of the other DECmuxs attached to this MUXserver.
    So, practically speaking, if DM300-8 servers are used, up to 128
    connections could be in use, but only 8 ports can be configured for
    reverse-TELNET connections, otherwise a TELNET connection which does
    not contain a  station_name or IP address (since the DECmux does not
    have an IP address) would not know which TELNET LISTENER 2007 the
    connection was for.  Is this correct?
    
    Thanks
    Larry DeGroff
    Network Support