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Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!ux1.cso.uiuc.edu!tank!shamash!nic.MR.NET!hal!ncoast!fmsystm!macy
From: macy@fmsystm.UUCP (Macy Hallock)
Newsgroups: comp.dcom.lans,comp.dcom.modems
Subject: Re: multiplexing serial lines
Keywords: PC/NOS
Message-ID: <104@fmsystm.UUCP>
Date: 20 Oct 89 00:25:15 GMT
References: <8091@microsoft.UUCP>
Reply-To: macy@fmsystm.UUCP (Macy Hallock)
Distribution: usa
Organization: F M Systems  Medina, Ohio USA
Lines: 36

In article <8091@microsoft.UUCP> bruceki@microsoft.UUCP (Bruce King) writes:
>
>  I don't know if this product exists, but I'd like to know.  In particular,
>I'd like to run 4 serial lines (300-1200 baud lines) into a black box, and
>run a single line out of it to a high speed modem.  When I get to where I'm
>going, I want to do the opposite.  
>
>  ------300 baud line-----\                       /---300 baud line----
>  ------1200 baud line-----\_X__telebit modem__X_/----1200 baud line---
>  ------300 baud line------/                     \----300 baud line----
>  ------1200 baud line----/                       \----1200 baud line--

A couple of suggestions...

First, you need a full duplex modem for the link you propose...
your best bet over a dialup line is a V.32 modem...a Telebit T2500
would be required, or a less expensive V.32 

The multiplexor should not be a problem...but most mux's have a fixed speed
on their ports.  Error correction should be a fuction provided by the mux,
not the highspeed modem.

My first impression is that you should talk to Multi-Tech about their
products.  There are other manufacturers out there who make this stuff
(Codex, UDS, Fujitsu)  DataRace has an interesting modem/mux combo 
unit that might be the right thing, too.

Multi-Tech Systems is 800-328-9717 or 612-631-3550.

Disclaimer: I am not an employee or agent for any modem mfr.  And
no one has offered me any kickbacks for promotion...(that's why
I'm still trying to pay for the kids' braces...)

Macy Hallock     150 Highland Dr.     macy@NCoast.ORG
F M Systems Inc. Medina, OH 44256     {uunet|backbone}!hal.cwru.edu!ncoast!macy
+1 216 723-3000  Fax +1 216 723-3223  uunet!aablue!fmsystm!macy