[net.dcom] Wanted: Info on data PBX's

roy@phri.UUCP (Roy Smith) (07/13/85)

	I've got a Vax with 40 terminals (maybe 16 are ever active
simultaneously).  We plan on getting another machine with 16-32 lines
soon.  Our accounting office also has a 68000 box with a few (4?)
terminals.  I want to get a switch so all the terminals, modems, and
machines can talk to each other; 64 lines on each side with potential to
expand to twice that should be plenty.

	So far, the best I've seen is an Equinox box, but it seems like
overkill.  It's expandable to over 1000 lines, and has provisions for
redundant everything for fault-tolerant operation.  I don't need these
capabilities, but I still have to pay for them; a 96 line system costs
about $17K.  Does anybody know of something smaller and cheaper?
Impartial advice or sales calls are equally welcome.

	I've never bought one of these things before.  Any pointers on
what questions I should be asking myself and the vendors?  Any pitfalls
to avoid?  Any features I should demand?  Do they all eat the ^S's and
^Q's emacs loves so much (as currently being discussed in net.emacs)?
-- 
allegra!phri!roy (Roy Smith)
System Administrator, Public Health Research Institute

bob@islenet.UUCP (Bob Cunningham) (07/18/85)

Another good reason for buying port selectors (PACXs, or similar jargon)
is that you can easily add terminals more cheaply than you normally would
by bying port/distribution boards for your systems.

We use Gandalf's and Micom's around here, but both Equinox and Develcon get
you more for the same price if you don't plan to expand past their limits.
On the other hand, don't underestimate your expansion needs (and always
have a spare port/terminal board or two on hand).

Once a connection is set up, it should be completely transparent to
whatever 8-bit data you throw thru it.  If it isn't, don't buy that brand.
The most common ways of breaking a connection depend upon either the
computer (or the terminal end) dropping DTR ... which has nothing to do
with the form of the data sent over the link.  The only time you might get
into ctrl-Q/ctrl-S difficulties with most of the port selectors on the
market is when you're also using some sort of stat mux together with it.

Things to demand from vendors:  firm quote on the system you want
configured with your initial number of port/terminal connections, and a
firm price on additional port/terminal boards, and ... don't forget
installation & shipping charges; have them get you manuals on a unit you're
interested to peruse before you decide (will give you a feel for what it
wil actually be like running one); a description on how support will be
provided (do they have an 800-number, local support, or what?);  and specs
on exactly what terminal/port speeds are supported, and under what
conditions the connections are fully transparent or not.

> ... I want to get a switch so all the terminals, modems, and
> machines can talk to each other; 64 lines on each side with potential to
> expand to twice that should be plenty.
> 
> 	So far, the best I've seen is an Equinox box, but it seems like
> overkill.  It's expandable to over 1000 lines, and has provisions for
> redundant everything for fault-tolerant operation.  I don't need these
> capabilities, but I still have to pay for them; a 96 line system costs
> about $17K.  Does anybody know of something smaller and cheaper?
> Impartial advice or sales calls are equally welcome.
> 
> 	I've never bought one of these things before.  Any pointers on
> what questions I should be asking myself and the vendors?  Any pitfalls
> to avoid?  Any features I should demand?  Do they all eat the ^S's and
> ^Q's emacs loves so much (as currently being discussed in net.emacs)?
-- 
Bob Cunningham  {dual|vortex|ihnp4}!islenet!bob
Honolulu, Hawaii