SUMMARY: IBM <-> UNIX Connections (400 lines)

[larry hughes]

I might also add another interesting connection method that we're
preparing to implement at Indiana University.

We have a 3090-300S that historically has been used as an administrative
machine.  However, we're currently bringing up an online library system
and other applications that are of interest to all faculty, staff, and 
students.  The 3090 runs ACCES/MVS, and is FEP'd with an Intel 9770.

Since we anticipate connections from PC's, Mac's, terminal servers,
high end workstations, and minis, we obviously wanted to offload the 
3270 protocol conversion from the 3090.  Additionally, we found that
the ACCES/MVS software multithreads the connections more optimally when 
there are fewer sources of connections.

Our solution consists of:

  (1) 3 Sun Sparcstations which autologin each inbound telnet
      connection (on port 23) as user TN3270, and automatically
      invokes tn3270 to pass them through to the 3090.

  (2) A modified version of the Berkely bind (named) code which
      load balances most of the connections to the Sparcs based
      on number of current users and CPU load (not round-robin).
      This obviously won't work for hosts that utilize caching
      nameservers), but will work for those that don't, as well
      as for the terminal servers, PCs, and Macs.

This description is vague, but you get the idea.  It's not up yet, 
but will be soon.  We're just ironing out the last few details, 
and waiting for the next semester to start.

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