[Info-vax] terminal servers etc

[Rich Jordan]

On Jan 5, 12:16 pm, hel... at astro.multiCLOTHESvax.de (Phillip Helbig---
undress to reply) wrote:
> I would like to connect some real terminals far away from my cluster to
> a LAT service on the cluster so that I can hit RETURN on the terminal
> and one of the nodes will offer the login prompt.  If I have the basic
> idea correct, I can connect the terminals to a terminal server via a
> serial connection then connect the terminal server to the LAN where it
> can talk to the cluster via TCPIP or LAT.
>
> I've used a similar setup, years ago, but have no idea how it was set
> up.
>
> Speed is not an issue since I can't type much faster than 100 b/s.  :-)
>
> Some questions (note: I'm not looking for actual instructions; I'll look
> them up if I decide to go this route):
>
> How difficult is this to set up on the VMS side?
>
> Is LAT preferable (easier, better) than TCPIP?
>
> I have stuff like DECserver 90TL, DECserver 90M.  Will this do what I
> want?  (I also have some DECserver 200MC and 250 but I assume the 90s
> are the better choice here.)
>
> The DECrepeater 90T is functionally equivalent to a 10 Mb/s hub (but
> amplifies the signal, hence a repeater and not a hub), right?
>
> T is TCPIP, L is LAT, TL is both, M is both and more?  Since a hub or
> repeater is essentially a dumb device, why can't it handle all protocols
> as long as the wiring is correct?
>
> Is the only network connection on the server the BNC coax connector?  If
> so, I'll probably need one of the repeaters in order to connect this to
> a twisted-pair network.  I have both standalone server and repeater as
> well as some which connect to a backplane (and have the backplane as
> well).  Will the backplane provide a network connection between server
> and repeater?  (If so, I might be able to avoid BNC.)

If you have a choice, and don't need full modem control, use the
DECserver 90M.  The 90TL and other units are less flexible; they only
run the original DECserver software (the TL adds TCPIP).  The 90M can
run the classic software but also can run the NAS software, the more
advanced type that provides a lot more capabilities (which, who knows,
you may want to try down the road).  The 90M can also self-boot from
flash memory (albeit rather slowly); if you want to use the DECserver
for console access, that means you'd actually _get_ console access
even if your DECserver boot loading nodes are offline and unavailable.

My own preference on the home network is to use LAT.  It is
drastically more responsive, especially if you're scrolling a large
doc and hit the hold screen key (or ctrl-Y to stop a runaway type,
etc).  With the 90M (or the TL) you can still have TCPIP configured
and usable also if you want to connect a serial device to the
DECserver and make it accessible via TCPIP, or just to telnet outbound
direct from your terminal.  We (work) still have locations using
serially connected printers via TCPIP$TELNETSYM queues and LATSYM via
DECserver 700 and 90M units.