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From: welch@xcf.Berkeley.EDU (Sean N. Welch)

Newsgroups: comp.dcom.isdn,news.answers

Subject: ISDN Frequently Asked Questions (and Answers) [Monthly posting]

Summary: This posting contains a list of Frequently Asked

	Questions (and their answers) about Integrated Services

	Digital Networking (ISDN).  It should be read by anyone

	who wishes to post to the comp.dcom.isdn newsgroup.

Keywords: ISDN FAQ

Message-ID: <isdn-faq_711068602@xcf.Berkeley.EDU>

Date: 13 Jul 92 23:02:23 GMT

Article-I.D.: xcf.isdn-faq_711068602

Expires: 26 Aug 1992 23:03:22 GMT

Reply-To: welch@xcf.Berkeley.EDU (Sean N. Welch)

Followup-To: comp.dcom.isdn

Organization: Experimental Computing Facility, U.C. Berkeley

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Approved: news-answers-request@MIT.Edu

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NNTP-Posting-Host: xcf.berkeley.edu

Originator: welch@xcf.Berkeley.EDU





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)

