Message from discussion help me build a modem pool

Newsgroups: comp.dcom.servers,comp.dcom.modems
Path: nntp.gmd.de!Germany.EU.net!EU.net!uunet!ksmith!keith
From: ke...@ksmith.com (Keith Smith)
Subject: Re: help me build a modem pool
Organization: Keith's Public Access Computer System
Date: Sat, 23 Jul 94 03:00:59 GMT
Message-ID: <1994Jul23.030059.28816@ksmith.com>
References: <2vul32$qtr@baird.xap.com>
Lines: 48

In article <2vul32$...@baird.xap.com> you write:
>I am building a dial-up modem pool.  I have been looking at terminal 
>server advertising and need a reality check.  I would like to start 

Yea,  Terminal servers suck.

Here's why in a nutshell:

Data from a terminal on a T/S to a cpu under telnet:

Terminal --> T/S --> TCP/IP Packet --> Ethernet MAC --> TCP/IP Packet ->
                                      ^System(s) loading begins here
Target System Kernel -> telnet demon -> pty -> termio/asy kernel
routines -> ttyp -> application

Same data with a CPU BUS card (like digi EISA C/X)

Terminal -> C/X -> termio/asy kernal routines -> application.
                 ^ System load begins here.

Left off time accross the BUS although sending an empty TCP/IP packet
(say with 1 or 2 chars in it) from the NIC to the CPU is much less
efficient than a memory mapped port.

Not to mention the load if the ethernet or whatever is running anything
ELSE besides the terminal server.  If you dedicate an entire E-net for
JUST Terminal servers it's better but you still waste all that CPU
translating and packetizeing.

>with 10 dial-up lines and be able to expand to 60.  All advise and 
>comments regarding architecture, operation, and specific equipment 
>appreciated. 

I would suggest SCO or SVR4 on a 486/66/100 or Pentium based EISA setup,
with 32-64MB of RAM, and a Digi EPC/X.  Very fast, with low character
latencies, make it excellent for interactive work, as well as uucp style
connections, or non-windowed file transfer.  Use NFS for remote file
access, and you let your dial-in cpu act as a firewall if need be.

If money is no object, I would use rack mount MultiTech modems with all
the monitor snivel gear, Otherwise I would buy 2834's or 1432's and
just stack them to the ceiling, with wall bar outlets for the
transformers.
-- 
Keith Smith aka Digital Designs                 ke...@ksmith.com
5719 Archer Rd.                    Free Usenet News and Internet Mail Services
Hope Mills, NC 28348-2201         All 28K/14K Modems  (910) 423-4216/7389/7391
Somewhere in the Styx of North Carolina ...         14K-V.32/28K-V.34/28K-V.34