Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!hayes!tnixon
From: tnixon@hayes.uucp
Newsgroups: comp.dcom.modems
Subject: Re: PC X.25 dialup
Message-ID: <3945.2832805a@hayes.uucp>
Date: 16 May 91 12:51:38 GMT
References: <1991May15.185048.14878@cbnewse.att.com>
Distribution: na
Organization: Hayes Microcomputer Products, Norcross, GA
Lines: 49

In article <1991May15.185048.14878@cbnewse.att.com>,
mccoy@cbnewse.att.com (earl.mccoy) writes: 

> I have followed the interesting discussion concerning V.32 and V.42 modems. 
> Does anyone have details about having a PC modem make an ordinary
> (non-ISDN) telephone call to a public X.25 network access point and
> then having an X.25 call setup procedure establish an X.25 session
> to an X.25 host? The usual async call to an X.25 PAD does not interest
> me. What PC software/hardware/modem is needed? Thanks in advance.

Well, there's a couple of different ways to do this.  You can either 
buy a modem that has X.25 built in (like many of the Hayes V-series 
modems, including Ultra 96).  You can either use standard async comm 
software to do one session at a time, or use AutoStream-compatible 
software to support up to four simultaneous remote sessions.  The 
modem in this case includes a four-channel X.3/X.28/X.29 PAD 
function.

A second option is to have a modem that supports synchronous
communications (all Hayes Smartmodems 2400bps and above, and many
from other manufacturers), and an SDLC/HDLC card in your PC.  Then,
you can use X.25 software.  Sorry, I don't have any good suggestions 
for the software.

A third option is to have a modem that supports the Hayes AutoSync 
feature (again, all Hayes Smartmodems 2400bps and above).  AutoSync 
performs async-to-sync conversion inside the modem, allowing you to 
communicate with remote synchronous devices through the async port 
of your PC.  You avoid having to buy an SDLC/HDLC card for your PC, 
but you need to find X.25 software that is AutoSync-compatible 
(there is at least one such program; let me know if you're 
interested, and I can find out about it for you).

A fourth option is an "X.25 card" for your PC.  These are available 
from companies such as Eicon and Winterhalter, but are generally 
pretty expensive.  They often come with hardware and/or software 
features that allow the link to be shared with other PCs across some 
kind of bus or a LAN.  Some have built-on modems, and others require 
an external synchronous modem.

So, there are a lot of choices for connecting a PC to a PSPDN as a 
packet-mode terminal -- which is best for you depends on your 
application and the amount of money you have to spend.

-- 
Toby Nixon, Principal Engineer    | Voice   +1-404-840-9200  Telex 151243420
Hayes Microcomputer Products Inc. | Fax     +1-404-447-0178  CIS   70271,404
P.O. Box 105203                   | UUCP uunet!hayes!tnixon  AT&T    !tnixon
Atlanta, Georgia  30348  USA      | Internet       hayes!tnixon@uunet.uu.net