Milking machines


Roger Fajman (RAF%NIHCU.BITNET@CUNYVM.CUNY.EDU)
Fri, 02 Sep 88 12:43:31 EDT


Since the topic of communications servers has come up, it seems like a
good time to throw out my request for recommendations. We currently
have a Bridge CS/1 with 32 ports that is hooked up to our IBM mainframe
as a milking machine. We are talking 37x5 async ports, not protocol
converters. Our biggest complaint about the Bridge CS/1 is that it
does not negotiate the Telnet echo option correctly. It says that it
will echo and then expects the host to do it. The problem is that our
host does not echo, so the user must manually turn on echoing at their
end. The other problem with the CS/1 is that it is only 32 ports. We
will need a lot more in the future. The CS/1 can be configured with 64
ports, but then does not provode all the modem control signals that we
need. So far, 3Com/Bridge has not been very responsive in coming up
with a solution to the echo problem.

The cisco ASM communications server sounded attractive because it
supports up to 96 ports and they say that they do the echo negotiation
properly. So we got one in to test and found out in trying to figure
out how to configure it that it does not support all of the necessary
modem control signals. We need DSR and DCD to come up at the start of
a connection and go down at the end. A connection must be broken when
the host lowers DTR. And CTS must be lowered when the communications
server can't accept more data from the host (our host doesn't support
XON/XOFF flow control). Unfortunately, the cisco box can't do flow
control on CTS when it is doing the other modem control signals. So we
sent it back.

So, does anyone have any recommedations for other communications
servers for us to look at? We need lots of ports, proper echo
negotiation, support for break signals, and full modem control,
including hardware flow control. Don't tell me to junk the mainframe.
:-)



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