From: phil@BofA.com (Phil Schlesinger)
Newsgroups: comp.dcom.isdn
Subject: ISDN FAQ
Date: 27 Jan 93 19:55:04 GMT
Organization: Bank of America, Capital Products, RMTG #5906


Archive-name: isdn-faq
Last-modified: 1992/07/10
Version: 1.0

This is the first official monthly posting of this comp.dcom.isdn FAQ.  
Thank you all for your feedback on the initial draft.  (That is not to 
say that this is finished by any means.  Comments and suggestions are 
always welcome.)

There have been a number of additions and a few corrections since the draft
and the questions and answers are no longer direct quotes.  As new information
was brought to my attention, it became difficult to integrate direct quotes.
If there are any problems with my editing as opposed to quoting, I'm sure 
someone will let me know.  Now I just cite the sources at the end of each
question.  It still reads like it was written by 40 different people (because
it was) but after a few revisions, I hope to have a much smoother document.

I'm currently working on two additional questions having to do with the
nitty-gritty of how ISDN is carried and Switched 56 Kbps (S56) as it 
relates to ISDN.  Look for them next month.

[Note to the moderator of news.answers:  Sorry for all the trouble.  Thanks.]

-----
Sean N. Welch                       \\/                 welch@xcf.Berkeley.EDU
Experimental Computing Facility     /\\     University of California, Berkeley
-----

Frequently Asked Questions and Answers
comp.dcom.isdn 

These questions and answers have (for the most part) been extracted from 
comp.dcom.isdn.  

Questions with answers:

 1) What is ISDN?
 2) What does an ISDN network look like?
 3) What is ATM?
 4) What will it look like in my house/office?
 5) How does this compare to regular phone line services?
 6) Is caller ID available on ISDN?
 7) What do I get above and beyond plain old telephone service?
 8) What do ISDN phones cost? 
 9) Can you use existing telephone equipment with the voice portion?
10) How do I find out about getting ISDN in my area?
11) Where can I find what all of these acronyms mean?
12) Who is shipping what?
13) How about that SPARCstation 10?
14) Why does certain ISDN TE only work with a specific ISDN switch?
15) Where can I read more?
16) Who do I have to thank for this list?

Questions for which I have not yet put together an answer, but for which I 
am accepting suggestions:

 a) What is ISDN-1?
 b) What is the status of ISDN-1?
 c) What is B-ISDN and what does it have to do with ISDN?

Suggestions for additional questions and answers are appreciated.

---

1)  What is ISDN?

ISDN stands for "Integrated Services Digital Networks", and it's a CCITT 
term for a relatively new telecommunications service package.  ISDN is 
basically the telephone network turned all-digital end to end, using
existing switches and wiring (for the most part) upgraded so that the 
basic "call" is a 64 kbps end-to-end channel, with bit-diddling as needed 
(but not when not needed!).  Packet and maybe frame modes are thrown in 
for good measure, too, in some places.  It's offered by local telephone 
companies, but most readily in Australia, France, Japan, and Singapore, 
with the UK and Germany somewhat behind, and USA availability rather spotty. 

eleskg@nuscc.nus.sg (Winston Seah)
goldstein@carafe.enet.dec.com (Fred R. Goldstein)
paul@suite.sw.oz.au (Paul Antoine)
---

2)  What does an ISDN network look like?

A Basic Rate Interface (BRI) is two 64K bearer ("B") channels and a single 
delta ("D") channel.  The B channels are used for voice or data, and the D 
channel is used for signaling and/or X.25 packet networking.  This is the 
variety most likely to be found in residential service.  
Another flavor of ISDN is Primary Rate Interface (PRI). Inside the US, this 
consists of 24 channels, usually divided into 23 B channels and 1 D channel, 
and runs over the same physical interface as T1. Outside of the US then PRI 
has 31 user channels, usually divided into 30 B channels and 1 D channel.  
It is typically used for connections such as one between a PBX and a CO or 
IXC.  

kevinc@aspect.UUCP (Kevin Collins)
keyman@doorway.Eng.Sun.COM (Dave Evans)
turtle@newshub.sdsu.edu (Andrew Scherpbier)
---

3) What is ATM?

ATM (Asynchronous Transfer Mode) is a switching/transmission technique
where data is transmitted in small, fixed sized cells (5 byte header,
48 byte payload).  The cells lend themselves both to the time-division-
multiplexing characteristics of the transmission media, and the packet
switching characteristics desired of data networks.  At each switching
node, the ATM header identifies a "virtual path" or "virtual circuit"
that the cell contains data for, enabling the switch to forward the
cell to the correct next-hop trunk.  The "virtual path" is set up
through the involved switches when two endpoints wish to communicate.
This type of switching can be implemented in hardware, almost essential
when trunk speed range from 45Mb/s to 1Gb/s.

For more information, read comp.dcom.cell-relay.

art@acc.com (Art Berggreen)
---

4)  What will Basic Rate (2B+D) ISDN look like in my house/office?


An ISDN BRA U-Loop is 2 conductors from the CO to the customer premises. 
At the customer premises the U-loop is terminated by an NT1 (network 
termination 1). The NT1 drives a T-bus which is 4 wires. You can only have 
one device on the T-bus.  If you run the T-bus into a NT2 which has an S-bus 
(the passive bus) on the other side, you can connect up to 8 physical devices.
Electrically, the S and T reference points are the same (which is why they are
almost always referred to as the S/T bus).
Some NT1 may include between 24v and 53.5v power on the T-bus (making it 6 
wires), however this would be model/vendor dependent. There are also 8 wire 
T-bus connection (power + 2 extra?).
Australia and Europe are similar except the NT1 is owned by the PTT.  Either 
a ECH (Echo Canceling Hybird), like is used in the US, or a form of time 
division multiplexing using AMI is used to achieve bidirectional transmission 
an a single pair.

  +-+   S Bus   +-------+   T Bus   +-------+     U Loop    | 
  |?|=-=-=-=-=-=|  NT2  |===========|  NT1  |--------------[| wall
  +-+ 4-8 wires +-------+ 4-8 wires +-------+    2-4 wires  |

Some ISDN hardware plugs into the U loop, some with the T Bus, and 
some with the S-Bus.  In the US (at least) there is a power supply
between the wall and the NT1.

cliff@Berkeley.EDU (Cliff Frost)
curt@kcwc.com (Curt Welch)
dror@digibd.com (Dror Kessler)
glarson@bnr.ca (Greg Larson)
paul@suite.sw.oz.au (Paul Antoine)
pturner@eng.auburn.edu ( Patton M. Turner)
ronnie@cisco.com (Ronnie B. Kon)
---

5) How does this compare to regular phone lines?


The ISDN line may act like two independent phone lines with two numbers. 
Depending on the CO equipment, conferencing features etc. may be available 
(conferencing in the telephone switch).  BRA ISDN phones can support key-set 
features such as you would expect to get on an office PBX like:
     - multiple DNs / lines.
     - conferencing features.
     - forwarding features.
     - speed call.
     - call park.
     - call pickup.
     - ring again.

curt@kcwc.com (Curt Welch)
glarson@bnr.ca (Greg Larson)
---

6)  Is caller ID available on ISDN?


Caller ID (name or number display) may be supported (depending on the 
CO setup). The availability of caller ID for residential phones would 
depend on the capabilities of the local phone network and legislation 
allowing or disallowing caller ID.


curt@kcwc.com (Curt Welch)
glarson@bnr.ca (Greg Larson)
---

7)  What do I get above and beyond plain old telephone service?


One of the main features it that instead of the CO sending an AC ring
signal to activate your bell, it sends a digital package that tells WHO
is calling (if available), WHAT TYPE of call (speech, datacomm?), the
NUMBER DIALLED (maybe one of your aliases) and some other stuff. Your
equipment can then analyze this stuff and make an "intelligent" decision 
what to do with it. For example, a phone (with speech-only capacity) 
would completely ignore a datacomm call while a Terminal Adapter (ISDN 
"modem") or a phone with built-in datacom functions would respond to it. 
If you have several "aliases" tied to your line, you can program certain 
phones to answer calls for certain numbers only.  Datacomm calls contain 
baud rate and protocol information within the setup signal so that the 
connection is virtually instantaneous (no messing around with trying 
different carriers until both ends match).

curt@kcwc.com (Curt Welch)
etxorst@eos.ericsson.se (Torsten Lif)
---

8)  What do ISDN phones cost? 


The ISDN sets can cost between $180 for an AT&T 8503T ISDN phone from
Pacific Bell up to $1900 depending on what/how many features are needed.

keyman@doorway.Eng.Sun.COM (Dave Evans)
huntting@futureworld.advtech.uswest.com (Brad Huntting)
spike@coke.std.com (Joe Ilacqua)
---

9)  Can you use existing telephone equipment with the voice portion?


Terminal Adapters (TA'a) are available that will interface non ISDN terminal
equipment (TE), called TE2 to the S/T interface.  At least one RBOC provides 
a modem pool to allow for interchange of data with POTS subscribers.  Bellcore 
may approve a standard to allow a analog pair to interface to POTS sets from 
a NT1.  Also w/o a NT2 only one set can be connected to a B channel at a time.  This prevents 2 sets from participating in the same voice call.

pturner@eng.auburn.edu ( Patton M. Turner)
spike@coke.std.com (Joe Ilacqua)
---

10) How do I find out about getting ISDN in my area?


I work in the industry and suggest that you call the local telephone service
center office and ask for the name and number of the Marketing Product Manager 
for ISDN services.  If the service rep cannot make heads or tails of your 
question, ask to speak to the local service center manager for complex
business services.  This person should be able to direct you to the right
place.  For the Bell companies, this position is normally part of the
telephone company's core marketing staff at their headquarters location.

[I had been planning on listing particulars about local people to contact,
but since people change jobs and I wasn't planning on continually verifying
the names and numbers, instead I'll stick with listing the following.]

Bellcore national ISDN information clearing house hotline
800 992 4736

North American ISDN Users Forum (NIU) is an org. of ISDN-interested 
parties, coordinated by NIST (National Institute of Stds. and Tech.)
Contact:     Shukri Wakid
Advanced Systems Division
NIST
Gaithersberg, MD
(301) 975-2937/4853

bharrell@garfield.catt.ncsu.edu (Ben Harrell)
elitman@wam.umd.edu (Eric A. Litman)
evans@zk3.dec.com (Marc Evans)
varney@ihlpf.att.com (Al Varney)
---

11)  Where can I find what all of these acronyms mean?


An archive of telecommunication related files are maintained on 
lcs.mit.edu in the telecom-archives sub directory.  There is a 
glossary of general telecom acronyms, as well as an ISDN specific
list.

jms@romana.Tymnet.COM (Joe Smith) asks:
PMW1@psuvm.psu.edu (Peter M. Weiss)
---

12)  Who is shipping what?


[In this section, I'd like to expand a list of vendors shipping products
related to work in ISDN.  As it stands, the number is small, and the
information is sparse.  Additions and corrections are most welcome.]

[Also - Network World from November 18th, 1991 has an extensive listing
of products that were available at that time.  It ranges from terminal
adapters and PC cards to handsets to VME boards.  I'm in communication
with them trying to get permission to reproduce parts of the article 
here.]

Digital Subscriber Controler
AMD79C30A ISDN chip
Combines IEEE 1.430 S/T interface transceiver B channel LAPD channel 
processor and audio processor in a single chip.
Advanced Micro Devices
901 Thomson place
Mailstop 126 
Sunnyvale, CA 94086
(408) 732 2400 (voice)

ISDN <-> other network converters
Combinet
333 West El Camino Real, Suite 310
Sunnyvale, California 94087
(408) 522 9020 (voice)
(408) 732 5497 (fax)

ISDN <-> other network converters
DigiBoard
6400 Flying Cloud Drive
Eden Prarie, MN 55344
(612) 943 9020 (voice)
(612) 643 5398 (fax)

Q-bus board, router, and PC cards
Digital Equipment Co
REO2 G/H2
DEC Park
Worton Grange 
Reading
Berkshire
England

PC cards and standalone ISDN adapters
Gandalf 
Cherry Hill Industrial Center
Building 9
Cherry Hill, NJ 08002
1 800 GANDALF (voice)

Terminal adapters
Hayes ISDN Technologies
501 Second St., Suite 300
San Francisco  CA  94107
(415) 974-5544 (voice)
(415) 543-5810 (fax)
ISDN Product Manager: Chris Brock (cbrock@hayes.com)
ISDN Developer Support: Bill Taylor (btaylor@hayes.com)
ISDN Product Literature: Stephanie Lopez (slopez@hayes.com)
ISDN Sales: Jon Hendricks (jhendricks@hayes.com)


Terminal adapters
Motorola UDS
5000 Bradford Drive
Huntsville, AL 35805
(205) 430 8000 (voice)

PRI ethernet bridges
Network Express
Andrew Hasley
VP, Marketing
2200 Green Road
Ann Arbor, MI 48105
(313) 761-5005 (voice)
(313) 995-1114 (fax)

Multi-protocol router
Spider Systems
UK                         France                   Germany
Spider Systems Limited     Spider Systems SA        Spider Systems Limited
Spider House               Les Algorithmes          Schadowstrasse 52
Peach Street               Saint Aubin 91194        D-4000 Dusseldorf 1
Wokingham                  Gif-sur-Yvette           Germany
England                    Paris Cedex              
RG11 1XH                   France
0734 771055 (voice)        (1) 69 41 11 36 (voice)  (0211) 93 50 120 (voice)
0734 771214 (fax)          (1) 69 41 12 27 (voice)  (0211) 93 50 150 (fax)

Handsets
Telrad Telecommunications, Inc.
135 Crossways Park Drive
Woodbury, New York 11797
(516) 921-8300
1 800 645-1350

---

13)  How about that SPARCstation 10?


FYI, the hardware on the SS10 supports 2 B channels (64K+64K) and 1 D channel
(16K) for a grand total 144K in marketing speak. On *each* BRI (Basic Rate
Interface).  The "DBRI" chip in the SS10 supports audio devices and *2*
Basic Rate Interfaces. Typically you might use both B channels for data, 
1 channel for voice and 1 channel for data, or 1 channel for data to 1 point 
and 1 channel for data to another point.  In some parts of the world it's also
popular to run X.25 over the D channel. 

Info from the SPARCstation 10 full announcement e-mail:

  - What Becomes Available When:
        o ISDN
            Chip on the motherboard                     Q3 CY92
            ISDN Drivers on Solaris 2.x                 Q4 CY92 Solaris 2.x
            Teleservices API                            Q1 CY93 Solaris 2.x
            Wide Area Networking software               Q1 CY93 Solaris 2.x
            The chip on the motherboard provides a BRI (basic rate interface) 
            ISDN connection that is integrated with workstation audio.  
            The drivers provide a low level interface to the hardware.  
            The Teleservices API enables application development for 
            workstation/telephony integration - providing functions like 
            call setup, transfer, hold, confer, etc.  The API is hardware 
            independent so that it will work with third party non-ISDN 
            telephony hardware and software.  The WAN software enables
            data communication - running IP over ISDN (in other words, 
            applications that run over ethernet will run over ISDN).  
            In the first release, Sun will support data communications 
            in the US (for the AT&T 5ESS switch), the UK, France, Germany 
            and Japan.  We will support voice services in the US (for 
            the AT&T 5ESS switch) only. 

dank@blacks.jpl.nasa.gov (Dan Kegel)
kessler@Eng.Sun.COM (Tom Kessler)
---

14)  Why does certain ISDN TE only work with a specific ISDN switch?


In the bad current days before National ISDN-1, the ATT 5ESS switches and 
Northern Telecom DMS100 switches speak different call setup dialogues. That's
why you will see ISDN TE listed as 5ESS, DMS100 or both.

Jim.Rees@umich.edu (Jim Rees)
jerry@watchman.sfc.sony.com (Jerry Scharf)
---

15)  Where can I read more?


"ISDN In Perspective"
Fred R. Goldstein
Addison-Wesley
ISBN 0-201-50016-7

"ISDN: Concepts, Facilities, and Services"
Gary Kessler
ISBN 0-07-034242-3

"ISDN and Broadband ISDN" (2nd edition)
William Stallings
Macmillan
ISBN 0-02-415475-X

The 1990 ISDN Directory and Sourcebook
Phillips Publishing Inc.
7811 Montrose Road
Potomac, MD  20854     
(301) 340-2100

ISDN Sourcebook
Information Gatekeepers Inc.
214 Harvard Ave,
Boston, MA  02134     
(617) 232-3111  
1 800 323-1088

Bellcore ISDN Availability Report
WR-NWT-2102 ($103)
800 521 2673

AT&T Technical Journal special issue on ISDN
(Volume 65, Issue 1) January/February 1986

[If anyone can tell me how to get ahold of the next two documents in terms
of either ISBN, a publishing company, or an ftp site, I'd appreciate it.]

"A subnetwork control protocol for ISDN circuit switching"
Leifer, Gorsline, & Sheldon

"Multiprotocol Interconnect on X.25 and ISDN in the Packet Mode"
Malis, Robinson, & Ullmann

EFFector. Issue 2.01, Issue 2.06, Issue 2.08
ftp.eff.org:pub/EFF

AT&T Documents
--------------
"5ESS(rg.tm) Switch National ISDN Basic Rate Interface 
Specification - 5E8 Software Release"
AT&T document number 235-900-341
 
"5ESS(rg.tm) Switch ISDN Basic Rate Interface 
Specification - 5E7 Software Release" {Custom BRI}
AT&T document number 235-900-331
 
"5ESS(rg.tm) Switch ISDN Primary Rate Interface 
Specification - 5E7 Software Release"
AT&T document number 235-900-332
 
"5ESS(rg.tm) Switch Interface Specification to a
Packet Switched Public Data (X.75) Network -
5E8 Software Release"  [as in CCITT X.75]
AT&T document number 235-900-317
 
"5ESS(rg.tm) Switch X.75' Intranetwork Interface
Specification - 5E8 Software Release"
  [as in Bellcore's TR-000310]
AT&T document number 235-900-325
 
"5ESS(rg.tm) Switch Documentation Description
and Ordering Guide"
  [list/description of 5ESS documents]
AT&T document number 235-001-001
 
AT&T documents ordering:
1-800-432-6600 USA
1-800-225-1242 Canada
+1 317 352-8557 elsewhere
AT&T Customer Information Center
Order Entry
2855 N. Franklin road
Indianapolis, IN 46219    
(317) 352-8484 (fax)

Northern Telecom Documents
--------------------------

NTP 297-2401-100        ISDN System Description
NTP 297-2401-010        ISDN Product Guide

---

16)  Who do I have to thank for this list?


Lots of people, in one way or another.

sorflet@x400gate.bnr.ca (Winston WL Sorfleet)
Jim.Rees@umich.edu (Jim Rees)
PMW1@psuvm.psu.edu (Peter M. Weiss)
SYSGAERTNER@cygnus.frm.maschinenbau.th-darmstadt.de (Mathias Gaertner)
apsteph@cs.utexas.edu (Alan Palmer Stephens)
art@opal.acc.com (Art Berggreen)
awillis@athena.mit.edu (Albert Willis)
bharrell@garfield.catt.ncsu.edu (Ben Harrell)
blsouth!klein@gatech.edu (Michael Klein)
cliff@Berkeley.EDU (Cliff Frost)
craig@aland.bbn.com (Craig Partridge)
curt@kcwc.com (Curt Welch)
dank@blacks.jpl.nasa.gov (Dan Kegel)
dror@digibd.com (Dror Kessler)
dwight@hyphen.com (Dwight Ernest)
earle@poseur.JPL.NASA.GOV (Greg Earle - Sun JPL on-site Software Support)
eleskg@nuscc.nus.sg (Winston Seah)
elitman@wam.umd.edu (Eric A. Litman)
etxorst@eos.ericsson.se (Torsten Lif)
evans@zk3.dec.com (Marc Evans)
glarson@bnr.ca (Greg Larson)
goldstein@carafe.enet.dec.com (Fred R. Goldstein)
huntting@futureworld.advtech.uswest.com (Brad Huntting)
jerry@watchman.sfc.sony.com (Jerry Scharf)
jik@pit-manager.MIT.EDU (Jonathan I. Kamens)
jms@romana.Tymnet.COM (Joe Smith)
kessler@Eng.Sun.COM (Tom Kessler)
kevinc@aspect.UUCP (Kevin Collins)
keyman@doorway.Eng.Sun.COM (Dave Evans)
kph@cisco.com (Kevin Paul Herbert)
lmarks@vnet.ibm.com (Laurence V. Marks)
paul@suite.sw.oz.au (Paul Antoine)
pturner@eng.auburn.edu (Patton M. Turner)
rachelw@spider.co.uk (Rachel Willmer)
rdavies@janus.enet.dec.com (Rob Davies)
rogers@eplrx7.es.dupont.com (Wade T. Rogers)
ronnie@cisco.com (Ronnie B. Kon)
sanjay@media.mit.edu (Sanjay Manandhar)
spike@coke.std.com (Joe Ilacqua)
tnixon@hayes.com (Toby Nixon)
turtle@newshub.sdsu.edu (Andrew Scherpbier)
varney@ihlpf.att.com (Al Varney)
wb8foz@scl.cwru.edu (David Lesher)