NetNews Usenet Archive 1992 #30/NN_1992_30.iso/spool/comp/dcom/isdn/973

Internet Message Format | 1992-12-14 | 1.6 KB

Path: sparky!uunet!dtix!oasys!curt
From: [e-mail] (Curt Welch)
Newsgroups: comp.dcom.isdn
Subject: Re: The ISDN network
Message-ID: <[e-mail]>
Date: 14 Dec 92 06:07:19 GMT
References: <[e-mail]> <[e-mail]>
Reply-To: [e-mail] (Curt Welch)
Organization: Carderock Division, NSWC, Bethesda, MD
Lines: 27

>>Most ISDN terminal
>>equipment even comes equipped with rj-11 jacks so you can plug in analog
>>equipment without buying a separate ISDN voice set.

In comp.dcom.isdn, [e-mail] (Brent Capps) writes:
>So here's the situation.  I've got a modem plugged into a TA on my
>premises when a call comes in.  How do I determine whether the caller is
>analog or digital?  I can't listen for tones, because modem tone is
>supposed to be generated by the *receiving* party.

Here's one way it works:

The Hayes ISDN System Adapter (I think I have the right name) acts as
both a POTS TA, and as a ISDN digtal modem.  You can plug a pots phone
or standard analog modem into it.  When an ISDN data call comes in,
it's answered by the ISDN System Adapter.  When a voice call (i.e.
analog modem call) comes in, it's routed out the POTS line to the
analog modem.

As other's have pointed out, once ISDN becomes more wide spread, you
will start seeing the ISDN modems that support all the old analog
standards as well.  How is this any different than all the analog
modems having to support all the old slower (2400, 1200, 300, etc)
standards?  Backward compatibility has been a standard feature
for the last 5 generataions of modems.

Curt