[Info-vax] terminal servers etc

[Bart Zorn]

On Saturday, January 5, 2013 7:16:06 PM UTC+1, 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 
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> 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 
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> 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?
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> 
> 
> Is LAT preferable (easier, better) than TCPIP?
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> 
> 
> 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.)
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> 
> 
> The DECrepeater 90T is functionally equivalent to a 10 Mb/s hub (but
> 
> amplifies the signal, hence a repeater and not a hub), right?
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> 
> 
> 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 
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> as long as the wiring is correct?
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> 
> 
> 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 
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> well as some which connect to a backplane (and have the backplane as 
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> well).  Will the backplane provide a network connection between server 
> 
> and repeater?  (If so, I might be able to avoid BNC.)

I would suggest using only the 90M, because that is the only one that has twisted pair ethernet. It has both LAT and TCP/IP and it does not need a MOP or bootp load host because it has flash memory built in.

You will like the command interface: it has SET and DEFINE and of course SHOW. It has also CHANGE, which does what SET and DEFINE do combined in a single command!

The DEChub 90 itself has only a 10baseT connection. But all plugged in devices are connected to that same segment: it is a hub. You should put a 50 Ohm terminator on the BNC of the DEChub if you do not connect a coax cable.

Bart