Dennis,

     My current WAN environment includes Tellabs stat muxes hooked to DTC48's
     that can handle up to 32 devices per mux up to 9600 baud per port.  The
     muxes handle XON/XOFF flow control to printers and they also stop the
     spooler on the HP3K if the remote printer goes off the air for any reason
     without losing printouts to the bit bucket.  With an additional mux
     concentrator box, I believe that you can have up to four 32-port muxes
     sharing one 56K leased line.

     One requirement to make all of this magic happen is that the DTC48
     MUST have modem connect (DB25) ports to handle all of the signalling
     required.  An additional requirement is that the DTC (DB25 to RJ45) plug
     must be wired a certain way for printers, and differently for terminal
     ports.

     We are in the process of moving off of this technology which has been
     working here for several years and going to all router-based connections to
     my WAN.  (plug ON) So, if you or others are interested in a time-tested
     method for MUX connections, I may be able to provide you with the necessary
     equipment at a good price.  Drop me a line or give me a call at (215)
     699-7400. (plug OFF)  Obviously, first come, first served!

     John Hornberger
     Sr. Systems Programmer
     General Signal Services
     [log in to unmask]

______________________________ Reply Separator _________________________________
Subject: DTCs and stat muxes...help!
Author:  Dennis Barnes <[log in to unmask]> at Internet2
Date:    7/9/97 5:26 PM


We have a remote campus which has been operating quite successfully with a
Codex 6015 stat mux which provides 16 ports, 3 of which are configured as
spooled printers.  The campus has experienced phenomenal growth and we have
purchased an Infotron Commander 32 in order to expand access to our HP-3000
series 957.  We have a DTC-48 and we're trying to use LaserJet II, III and
IV as spooled printers on a type 18 port.

So far, we have been unsuccessful at getting the spooled printers to work.
 We've tried various configurations, but the flow control seems to fail
between the local multiplexer and the host.  The result is lost pages in any
report longer than six or seven pages.  The parity settings available on the
Infotron mux are odd, even, space, mark.  LaserJets seem to expect no parity
and that is how the Codex mux was set.

Is anyone using Infotron multiplexers with an HP-3000?  If so, have you
solved the dilemma I've described?

Perhaps there is another multiplexer vendor who can handle more than 16
ports and spooled printers?

Any help would be greatly appreciated.  Fall registration will be upon us
soon, and we need to have a solution in place before it begins.  Thanks.

Dennis Barnes
Director of Computer Services
Wharton County Jr. College
911 Boling Hwy.
Wharton, TX 77488

Internet: [log in to unmask]
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