Frequently Asked Questions and Answers

comp.dcom.isdn

These questions and answers have (almost entirely) been extracted from

comp.dcom.isdn. Please post any comments or new material that you

have, or email them to the current FAQ editor, cherkus@unimaster.com.

In particular, the vendor equipment chart is incomplete. If you want

to share vendor equipment info, just cut and paste the headers from the

chart below and create a new entry for the new information, and send it

to me.

This FAQ consists almost entirely of information posted to this group.

There are a fair number of holes and there may be some outdated

information in it. There is no claim of completeness or guarantee of

accuracy of any kind, or no warranties for merchantability or fitness

for a particular purpose. If you have some useful information that you

would like to share, email it to me. My goal is to have the FAQ mirror

the information provided to the newsgroup itself. The next-to-last

section of this FAQ gives references that provide much more information

than this FAQ does.

I would like to thank Sean Welch for creating the previous edition

of the FAQ. His work is still responsible for the majority of the

information gathered here. I hope to continue the fine example that

Sean has set.

Questions with answers:

1) What is ISDN?

2) What does an ISDN network connection look like?

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

4) Can the existing local loop lines be reused for ISDN?

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) What is National ISDN?

11) What is the NIUF?

12) What is ATM?

13) What is B-ISDN?

14) What is BONDING?

15) Data Encapsulation for IP over ISDN

16) Full Motion Video over ISDN

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

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

19) What are the relevant standards?

20) Who is shipping what?

21) How about that SPARCstation 10?

22) How about that IBM Waverunner?

23) What is a SPID? How come my ISDN device won't work without one?

24) Will an ISDN terminal equipment that works in one country

work properly when it is installed in another country?

25) Will ISDN terminal equipment that works with one vendor's ISDN

switch work properly when it is used with another vendor's switch?

26) Do different manufacturers Terminal Adaptors interoperate when used

asynchronously?

27) Why do I get only about 19.2k throughput from my TA?

29) How long should call setup take when using a TA?

29) Can I get on-line National ISDN information from Bellcore?

30) Where can I read more?

31) 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 programming API's are useful for creating ISDN applications?

(e.g. Sun, Microsoft TAPI, NIUF ASI, ETSI(?), CAPI(?), more(?))

What are their strengths and weaknesses?

1) What is ISDN?

ISDN stands for "Integrated Services Digital Networks", and it's a TSS

(formerly 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 somewhat more behind.

2) What does an ISDN network connection look like?

[ Ed Note: I edited this section a lot, mainly to move

the discussion of NT devices to the next section. ]

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.

Equipment known as a Terminal Adapter (TA) can be used to adapt these

channels to existing terminal equipment standards such as RS-232 and

V.35. This equipment is typically packaged in a similar fashion to

modems, either as standalone units or as interface cards that plug into

a computer or various kinds of commmunications equipment (such as

routers or PBXs). TAs do not interoperate with the modem; they

replace the modem.

There may be cases where there is no need to interface to existing

terminal equipment, or to emulate exisiting terminal equipment, or

there may equipment with synchronous interfaces is present. In these

cases, standalone units or computer interfaces can provide high speed

synchronous connections to the B channels without converting to an

asynchronous standard.

Another common type of equipment can be used to implement a bridge

between local area networks using the ISDN channel to transport the

data. These devices typically provide features such as demand

dialing and/or data compression.

Of course, more traditional devices such as telephones and fax machines

can be attached to the BRI, assuming they have the proper interface

hardware and software.

Another flavor of ISDN is Primary Rate Interface (PRI). Inside North

America and Japan, 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 these areas the PRI has 31 user channels,

usually divided into 30 B channels and 1 D channel and is based on the

E1 interface. It is typically used for connections such as one between

a PBX (private branch exchange, a telephone echange operated by the

customer of a telephone company) and a CO (central office, of the

telephone company) or IXC (inter exchange carrier, a long distance

telephone company).

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

[ Ed Note: My attempt to make this section accurate in the last

version of the FAQ fell short. I've tried to correct it and

I'm still looking for comments... Thanks to Mark Anderson,

mea@intgp1.att.com, for pointing out the major mistakes. ]

An ISDN BRI U-Loop is 2 conductors from the CO (telephone company

central office) to the customer premises. Its maximum length may be

5.5 km (18000 ft). The equipment on both sides of the U loop has to be

carefully designed to deal with the long length of the U loop and the

noisy environment it operates in.

At the customer premises the U-loop is terminated by an NT1 (network

termination 1) device. The NT1 drives a S/T-bus which is usually 4

wires, but in some cases it may be 6 or 8 wires. In these optional

cases, the extra wires are used provide power to operate telephones

when normal power fails. Alternately, 'phantom' power may be derived

from the standard four wires. Outside of North America emergency mode

operation provides power for basic voice service only in the case of

loss of local power. In emergency mode operation the NT1 receives up

to 1.2W from the central office. In North America there is no provision

for emergency mode operation.

The name of the S/T bus comes from the letters used in the ISDN

specifications used to refer to two reference points, S and T. Point T

refers to the connection between the NT1 device and customer supplied

equipment. Terminals can connect directly to NT1 at point T, or there

may be a PBX (private branch exchange, i.e. a customer-owned telephone

exchange). When a PBX is present, point S refers to the connection

between the PBX and the terminal. Note that in ISDN terminology,

"terminal" can mean any sort of end-user ISDN device, such as data

terminals, telephones, FAX machines, etc.

This picture shows what an residential ISDN connection looks like.

Point T Point U |

+--------+ 4-8 wires +-------+ 2-4 wires |

|Terminal|-----+-----| NT1 |-------------[| wall (to telco CO)

+--------+ | +-------+ |

+--------+ | |

|Terminal|-----+

+--------+ |

:

+--------+ |

|Terminal|-----+

+--------+

The T bus is a multipoint bus in this configuration. It is sometimes

called the passive bus because there are no repeaters on the line

between the NT1 and the devices. It can be implemented using the same

cable and connectors as is 10 base T Ethernet. There may be up to 8

devices on the S/T bus. The bus may be formed with splitters and T

connectors - it is a bus, not a star. The D channel is used to control

the attachment of the one to eight devices to the two B channels. No

two devices attach to the same B channel at the same time.

In this configuration, the major function of the NT is to allow more

than one device to have access to the 2 B channels provided by the ISDN

BRI. For instance, you may have an ISDN telephone, an ISDN fax and an

ISDN computer interface attached to the BRI. Each device can listen

for calls and only connect to a B channel when it identifies a message

requesting a service it can provide.

The NT1 only implements part of the channel sharing scheme; the other

devices participate as well, and the communication protocol used by the

NT1 and the other devices is an integral part of the scheme. The NT1

also performs other functions; it translates the bit encoding scheme

used on the lines between it and the telephone company (the U loop) to

the encoding used between it and the devices. These schemes are

different because the device to NT encoding was designed to enable

channel sharing whereas the NT to telco encoding was designed to allow

transmission across long distances.

In the United States, the customer pays for the NT device, so don't

forget to include the cost of this unit in your cost estimates, or if

you don't need the multiple device attachment feature, try to find a

device that does not require the NT device (i.e. it attaches directly

to the U loop). If you are not in the United States the telephone

company provides the NT device, but remember there is no such thing as

a free lunch - you are probably paying for it through increased rates,

or increased taxes, etc. (flames to sci.economics or alt.talk.politics).

Unfortunately, the NT1 is not an inexpensive device. It has to convert

between the signalling used on the U loop (which is operates over long

distances (5.5 km, 18000 ft) in a noisy environment and does not have

to deal with contention between devices) and the signalling of the S/T

bus (which operates over shorter distances in a quieter environment but

it does have to deal with contention between devices and other protocol

functions). It also provides diagnostic functions such as loopback

mode, and it may have to provide power, as descibed above.

This picture shows what an ISDN connection looks like when a PBX is

present.

In this configuration, the wires at points S and T are point to point

links. Electrically, the S and T points are the same, which is why the

name S/T bus is almost always used. This makes sense; the terminal

should see the same physical interface whether it is hooked up with or

without a PBX. But, logically they are different. The telephone

company needs to know that there is a PBX between itself and the user

so that it can coordinate its efforts with the PBX. So, in cases where

the difference is important, the specifications use the S and T

terminology.

When there is no PBX in the configuration, the NT1 device is usually a

standalone device that is packaged a lot like a modem: in a small box

when there are only a few, and in a rackmount when you need a lot of

them. In the United States, the customer buys the NT1 but in most of

the rest of the world the telephone company provides the NT1. When

there is a PBX the rackmounted NT1s are quite common. Also, when

there is a PBX the use of PRI lines instead of BRI lines is common.

4) Can the existing local loop lines be reused for ISDN?

The ISDN pairs are the same wires as used for regular telephone

service. If you became an ISDN user at home, the same wire pair that

now provides your telephone service would be used to provide ISDN

(assuming you no longer have the regular line).

Most of the lines do not require any special conditioning. Yes, if

a line has load coils on it they must be removed, BUT load coils

are usually only found on existing lines that are 15,000 feet or

longer. As to lines with bridge taps, the 2B1Q line transmission

scheme (not to be confused with 2B + D channelization) is tolerant

of a certain amount of bridge taps and, therefore it is only a minimal

subset of existing lines (lines with bridge taps whose total length is

greater than 3000 feet for the bridge taps) that would require

special "de-conditioning."

With those things as the criteria, (in North America) we find than

generally around 90% or so of existing telephone lines need no

"de-conditioning" in order to be used for ISDN BRI service.

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). BRI ISDN phones can support key-set

features such as you would expect to get on an office PBX like:

- multiple directory numers per line.

- multiple lines per directory number.

- conferencing features.

- forwarding features.

- voice mail features.

- speed call.

- call park.

- call pickup.

- ring again.

- textual status displays.

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. The availability of Caller ID

relies on the underlying switching protocol used by the switches

that make up the telephone system (e.g. SS7).

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

Plain old telephone service is transmitted between the central office

to your home or office telephone set (or modem, or fax) in analog

form. At the central office, the analog signal is converted to a

series of digital samples at a rate of 8000 samples per second. Each

sample is seven or eight bits in length. As the signals for a

telephone call move around the central office, or between central

offices, they are transmitted in digital form. Thus, a telephone call

consumes a transmission bandwidth of either 56 or 64 kilobits per

second. The theoretical (Nyquist) limit for the frequency response of

a signal sampled 8000 times per second is 4kHz. However, due to

various losses in the telephone system, the frequency response of an

ordinary telephone call is usually quoted as 3.1kHz. Ordinary

modem-based data transmission uses schemes for encoding data in an

analog signal so it fits in this 3.1kHz bandwidth. 14.4kbps is a

commonly available transmission rate at the high end of the scale.

With this transmission rate, over three-quarters of the bitrate handled

by the central office is wasted.

Notice that in telephony, 64kpbs means 64000 bits per second, whereas

in computer engineering 64k bytes typically means 65536 bytes.

ISDN brings the digital signal all the way to your home or desktop. With

ISDN, you can place a data call which uses all 56kbps or 64kbps, because

there is no need to convert the signal to analog in your modem and back

to digital at the central office. The availability of the full bandwidth

presents some interesting technological opportunities:

-- transmission of high-fidelity compressed audio

-- transmission of encrypted audio

-- transmission of lots of data

-- transmission of other compressed signals, such as video

Basic-rate ISDN (BRI) offers two channels of this service. In BRI, the

connection between your site and the central office offers 64kbps

bidirectionally on each channel. Each of these channels may be used

for a voice call, for circuit-switched data, or for X.25 packet

switched data. Thus, the existing POTS circuit can be conditioned to

carry two calls at the same time. (Your mileage may vary; you have to

specifically order and pay for the various services from your telephone

company, just as you have to order and pay for Call Waiting for an

ordinary phone line. Also, not all services are available everywhere;

X.25 connectivity between COs is a notable problem in the Greater

Boston area as of 9/93, for example.)

Incidentally, ISDN brings another interesting service to your home or

desktop: a highly reliable 8000Hz clock signal. In most cases, the

central office switches, long-distance carriers, and ISDN terminal

equipment all operate with exactly the same clock frequency. In a

real-time communications environment (like a voice phone call) this

means that there's no need to compensate for differences between the

sampling rates at each end of the call.

One of the other 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 DIALED (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).

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.

A recent report states that the price is $536.90 for an AT&T 7506 with

the RS-232 port on the back and $102.70 to get the 507A adaptor to hook

analog devices to my 7506.

Recent quotes were "$200" for a Coretelco 1800 and "$600" for a Fujitsu

SRS 1050.

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) What is National ISDN?

Because of the breadth of the international ISDN standards, there are a

number of implementation choices that vendors of ISDN equipment can

make. Given the number of choices vendors can make, different vendors

equipment may not interoperate. In the United States, Bellcore has

released a series of specifications to try to avoid these

interoperability problems. These are the National ISDN

specifications. Contact the Bellcore ISDN hot line listed below for

more information.

11) What is the NIUF?

North American ISDN Users Forum (NIUF) is an org. of ISDN-interested

parties, coordinated by NIST (National Institute of Stds. and Tech.)

Contact:

NIUF Secretariat

National Institute of Standards and Technology

Building 223, Room B364

Gaithersberg, MD 20899

(301) 975-2937 voice

(301) 926-9675 fax

(301) 869-7281 BBS 8N1 2400 bps

Bellcore has made the PostScript files for "A Catalog of National

ISDN Solutions for Selected NIUF Applications, Second Edition"

accessable via anonymous ftp from the machine info.bellcore.com.

This document has a tremendous amount of information about

ISDN products and vendors, among many other things. See the item

below for details.

12) 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.

One use of ATM is to serve as the core technology for a new set of ISDN

offerings known as Broadband ISDN (B-ISDN).

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

This group has a Frequently Asked Questions list; it is posted

to news.answers and is in various archives as cell-relay-faq.

13) What is B-ISDN?

Broadband ISDN refers to services that require channel rates greater than

a single primary rate channel. While this does not specificially imply

any particular technology, ATM will be used as the switching infrastructure

for B-ISDN services.

B-ISDN services are categorized as:

INTERACTIVE

Conversational -- such as videotelephony, videoconferencing, ...

Messaging -- such as electronic mail for images, video, graphics,...

Retrieval -- such as teleshopping, news retrieval, remote education,...

DISTRIBUTION

Without user presentation control -- electronic newspaper, electronic

newspaper, TV distribution

With user presentation control -- remote education, teleadvertising,

news retrieval

More information: ITU TSS Rec. I.211.

14) What is BONDING?

An inverse multiplexing method of the Bandwidth ON Demand

INteroperability Group, implemented by most (all?) inverse multiplexor

vendors to interoperate with inverse multiplexors of other vendors.

BONDING is a set of protocols developed by U.S. inverse multiplexor

that supports communication over a set of separate channels as if their

bandwidth were combined into a single coherent channel. For example it

supports a single 384 kb/s data stream over 6 64 kb/s channels.

The specification defines a way of calculating relative delay between

multiple network channels and ordering data such that what goes in one

end comes out the other.

Most (all?) vendors also have their own proprietary methods that

usually add features functions not present in BONDING mode 1. Mode 1

is the mode used for recent interoperability testing between vendors.

Chip Sharp at Teleos has made available electronic copies of the

BONDING (Bandwidth on Demand Interoperability Group) 1.0 and 1.1

specifications. The specs are available via WWW, gopher, anonymous

FTP, DECnet COPY, and AFS (see instructions below).

The following files are available:

- aaareadme-networks help file (in ascii text)

- bdmain.doc main body of BONDING 1.0 specification

(Word for Windows 2.0 format)

- bdmain.ps main body of BONDING 1.0 specification (Postscript)

- bdannex.doc annex of BONDING 1.0 specification (Word

for Windows 2.0 format)

- bdannex.ps annex of BONDING 1.0 specification (Postscript)

- bd_v1_1.doc changes for BONDING 1.1 specification (Word

for Windows 2.0 format)

- bd_v1_1.ps changes for BONDING 1.1 specification (Postscript)

Transfer Instructions:

WWW:

server: www.hep.net

URL: gopher://www.hep.net:70/11/info_center/networks/bonding

Gopher:

server: gopher.hep.net

Bookmark:

Name=Bandwidth on Demand Interoperability Group (BONDING) Documents

Type=1

Port=70

Path=1/info_center/networks/bonding

Host=gopher.hep.net

Anonymous FTP:

server: ftp.hep.net

directory: networks/bonding

DECnet COPY (only for those on HEP-NSI DECnet):

HEPNET::[ANON_FTP.NETWORKS.BONDING]

AFS:

/afs/hepafs1.hep.net/public/anon_ftp/networks/bonding

15) Data Encapsulation for IP over ISDN

A decision was made at the Amsterdam IETF to state that all systems

wishing to guarantee IP interoperability should implement PPP. Such

systems may also implement the Frame Relay or X.25 encapsulations, and

an RFC will be published delineating how, when it is known that the

encapsulations are limited to that set of three, they may be

distinguished by examination of the first correctly checksumed and HDLC

bit-stuffed packet.

There is an Internet Draft from the Point-to-Point Protocol Working

Group of the Internet Engineering Task Force that describes the use of

PPP over ISDN. This draft is named draft-ietf-pppext-isdn-NN.txt in

the internet-drafts Shadow Directories on nic.ddn.mil, nnsc.nsf.net,

nic.nordu.net, ftp.nisc.sri.com, munnari.oz.au, Germany.EU.net and on

many, many other mirror archives. This is also discussed in RFC 1356

by Malis, et. al.

The de facto standard in most European countries is an encapsulation

using simple HDLC in layer 1, X.75 (LAPB, usually I-frames) in layer 2

and, sometimes, T.70 in layer 3. X.75 happens to be a bit more crispy

especially using short hold mode and it is simpler. PPP has to be used

instead when the network doesn't provide the callers telephone number

eg. when emulating a modem or the callers number is lost on telephone

company borders. In this case, caller authentication has to be done

via PAP/CHAP instead.

16) Full Motion Video over ISDN

In ISDN, video isn't a "service being offered" - at least not for

low/midrange quality. You buy the proper equipment for both

subscribers, plug it in, and place the call. Just like speaking French

on ISDN isn't something being offered - it is something you just do,

yourself.

Video telephony over narrowband ISDN is governed by a suite of TSS

(formerly CCITT) interoperability standards. The overall video

telephony suite is known informally as p * 64, and formally as standard

H.320. H.320 is an "umbrella" standard; it specifies H.261 for video

compression, H.221, H.230, and H.242 for communications, control, and

indication, G.711, G.722, and G.728 for audio signals, and several

others for specialized purposes. A common misconception, exploited by

some equipment manufacturers, is that compliance with H.261 (the video

compression standard) is enough to guarantee interoperability.

Bandwidth can be divided up among video, voice, and data in a

bewildering variety of ways. Typically, 56kbps might be allocated to

voice, with 1.6kbps to signalling (control and indication signals) and

the balance allocated to video.

An H.320-compatible terminal can support audio and video in one B

channel using G.728 audio at 16 kb/s. For a 64 kb/s channel, this

leaves 46.4 kb/s for video (after subtracting 1.6 kb/s for H.221

framing).

The resolution of a H.261 video image is either 352x288 (known as CIF)

or 176x144 (known as quarter-CIF or QCIF). The frame rate can be

anything from 30 frames/second and down. Configurations typically use

a 2B (BRI) or a 6B (switched-384 or 3xBRI with an inverse multiplexer)

service, depending on the desired cost and video quality. In a 384kbps

call, a video conferencing system can achieve 30 frames/second at CIF,

and looks comparable to a VHS videotape picture. In a 2B BRI call, a

standard video phone can achieve 15 frames/second at CIF.

Those who have seen the 1B video call in operation generally agree that

the quality is not sufficient for anything useful like computer based

training - only for the social aspect of being able to *see* Grandma as

well as hear her (sort of like the snapshot pictures you make with that

$5 camera with no controls).

A 2B picture, on the other hand, is for all practical purposes

sufficient for remote education, presentations etc. Rapidly changing

scenes are still not very well handled, but as soon as the picture

calms down, the sharpness and color quality are impressive (considering

that only two plain phone channels are being used). With 2B+D being the

standard BRI, this kind of picturephone will be usable "everywhere"

(including private homes).

However, it should still be noted that 6xB or H0 does allow for dramatic

improvement in picture quality compared to 2xB. In particular, H.320

video/audio applications will often allocate 56kbps for audio, leaving

only 68.8kbps for video when using 2xB. On the other hand, using H0

would get you 326.4kbps for video with 56kbps for audio. Alternative

audio algorithms can improve picture quality over 2xB by not stealing

as many bits. Note that 6B is not identical to H0; the latter is a

single channel which will give you 80kbps above that of six separate B

channels. Inverse multiplexors can be used to combine B channels.

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

EURIE contact data:

Country Company name tel / fax

=========== ================ ====================== ===================

Austria PTT Austria Mr Michael Schneider +43 1 317 30 39

+43 1 31 3.13.66.63

Belgium BELGACOM Mr Egied Dekoster +32 2/213.46.49

+32 2/921.02.13

Denmark Tele Danmark Mr Soren Christensen +45 3399 6940

+45 3314 5625

Finland Telecom Finland Mr Terho Salo +358 31 243 22 67

+358 31 243 23 83

Finland The ATC Finland Mr Matti Tammisalo +358 0 606 35 08

+358 0 606 33 22

France France Telecom Mr Pascal Meriaux +331 44 44 53 59

+331 44 44 75 50

Germany DBP Telekom Mr Volker Fink +49 6151 83 30 67

+49 6151 83 50 68

Greece OTE Mrs Vas. Danelli +30 1 611 89 96

+30 1 805 20 64

Ireland Telecom Eireann Mr John Lawler +353 1 790 10 00

+353 1 677 49 41

Italy Iritel Mr Rocco Gentile +39 65 494 52 56

+39 65 94 20 54

Italy Itacable Mr Rolando Bottoni +39 65 734 45 23

+39 65 7 34 48 05

Italy SIP Mr Bernardino de Rito +39 6 36 88 40 38

+39 6 36 44 88

Luxembourg EPTL Mr Hubert Schumacher +352 49 91 56 56

+352 49 12 21

Netherlands PTT Telecom Ms Corinne der Kinderen +31 70 34 32 473

+31 70 34 39 747

Norway Norwegian Telecom Mr Odd Egil Asen +47 22 77 71 22

+47 22 2 0 78 00

Portugal TLP Mr Antero Aguilar +351 1 147 797

+351 1 544 796

Portugal Telecom Portugal Mr Jose Brito +351 1 35 04 710

+351 1 35 04 197

Spain Telefonica Espana Mr Fernando Moratinos +34 1 584 96 81

+341 584 95 58

Sweden Telia Mr Peter Ostergren +46 8 713 17 99

+46 8 713 73 62

Switzerland PTT Telecom Mr Jean-Yves Guillet +41 31 62 72 27

+41 31 6 2 85 26

UK British Telecom Mr JM Pickard +44 71 356 89 52

+44 71 796 91 20

UK Mercury Mr Clive Curt is +44 71 528 26 35

+44 71 528 20 66

Australia:

Telecom: 008 077 222 (voice), (07) 220 0080 (fax)

Belgium:

As from 01/01/94 ISDN is available in belgium on demand. All major

switching nodes of the national telecom company BELGACOM are digital

and a very fast increasing number of sub-nodes are converted to digital

connections. BRA (Basic Rate Access) can be connected in less than a

week in over 75% of the country. PRA may take longer depending on

geographical location. Caller ID is available on ISDN in Belgium

(using EURO-ISDN = ISDN fase 2 in Belgium) but only between ISDN

devices although it may be hidden by the caller.

BELGACOM: departement van de communicatie, ISDN-cel

paleizenstraat 42 - 4de verdieping

1210 Brussel

tel: 078/11.66.77 (free of charge)

Germany:

Deutsche Bundespost Telekom

IfN - Ingenierubuero fuer Nachrichtentechnik

Haidelmoosweg 52

D - 78467 Konstanz

Tel: +49 7531 97000-0

FAX: +49 7531 74998

United Kingdom:

British Telecom ISDN Helpdesk

0800 181514 from within the UK,

+44 272 217764 from outside.

Mercury Data Communication

0500 424194 from within the UK,

+44 81 914 2335 from outside.

North America:

North American ISDN Users Forum (NIUF): see item above

United States:

I 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.

Ameritech: 800-832-6328

Bellcore national ISDN information clearing house hotline:

800 992-4736

Bellcore's "ISDN Deployment Data", Special Report (SR) 2102.

Bellcore document ordering: US: 1-800-521-2673, other: 1-908-699-5800

Bell Atlantic: 800-570-ISDN (all except New Jersey Bell)

1-800-843-2255 x4736 (New Jersey Bell customers)

BellSouth 1-800-858-9413

Cincinatti Bell 513-566-DATA

You can call Pacific Bell at [800] 995-0346. This is an extensive

menu-driven system (yuck) that allows Pac Bell customers to enter their

area code and prefix to find out what services are available. It

doesn't tell you which switch, though. Pac Bell also operates a

Gopher server at gopher.pacbell.com or gw.pacbell.com. The Pac Bell

ISDN service center is at 1-800-4PB-ISDN.

GTE: Menu-driven information service at [800] 4GTE-SW5.

Florida, North Carolina, Virginia, and Kentucky: 1-800-483-5200

Illinois, Indiana, Ohio, and Penn. 1-800-483-5600

Oregon and Washington 1-800-483-5100

California 1-800-483-5000

Hawaii 1-800-643-4411

Texas 1-800-483-5400

Nevada Bell 702-688-7124 (contact Lyle Walters)

NYNEX: 1-800-438-4736, 800-GET-ISDN, 800-698-0817 or 212-626-7297.

Rochester Tele. 716-777-1234

Southwestern Bell (Texas)

Austin 512-870-4064

Dallas 214-268-1403

Houston 713-638-7000

San Antonio 512-351-8050

US West 303-896-8370 (contact Julia Evans)

Combinet "BBS":

By popular demand, the Combinet "BBS" providing information on ISDN

availability in many areas of the US is now available via the Internet.

The information is supplied by Bell Communications Research and various

Operating Companies and is updated periodically as new information

becomes available.

To access the service, telnet to bbs.combinet.com and login as

isdn (no password is required). After entering an area code and

three-digit prefix, the service displays the availability of ISDN.

Also displayed is information about carrier installation prices and

monthly charges.

For those without direct Internet access, the service continues to be

available on a dialup basis using a 2400 bit/sec modem at (408) 733-4312.

Intel:

If you want to know if you can get basic rate ISDN in YOUR LOCAL AREA

(anywhere in the U.S>), call the helpful folks at Intel on

1-800-538-3373, and ask for extension 208. They have lots of good FREE

info on ISDN availability, pricing, etc.

bharrell@garfield.catt.ncsu.edu (Ben Harrell)

elitman@wam.umd.edu (Eric A. Litman)

marc@Synergytics.COM (Marc Evans)

varney@ihlpf.att.com (Al Varney)

bernot@inf-wiss.uni-konstanz.de (Gerhard Bernot)

jhonan@kralizec.zeta.org.au (Jamie Honan)

dav@genisco.gtc.com (David L. Markowitz)

Peter Ilieve <peter@memex.co.uk>

p00210@psilink.com (Gerald L. Hopkins)

KUMQUAT@SMCVAX.SMCVT.EDU (Gary C. Kessler)

fenton@combinet.com (Jim Fenton)

james@kaiwan.com (James - The Keeper)

stamp@cc.bellcore.com (stamp,scott)

we34329@is1.vub.ac.be (Sven De Kerpel)

---

18) 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)

----

19) What are the relevant standards?

There are numerous TSS (formerly CCITT) standards on ISDN. References

in the book bibliography (especially Stallings and appendix B of

Kessler) contain more details.

Q.921

(aka I.441) "ISDN User-Network Interface Data Link Layer Specifications", 1988

The D channel protocol. Found in Blue book Fascicle VI.10

Q.931

(aka I.451) "ISDN User-Network Interface Layer 3 Specification for Call control"

1988. The messages that are sent over the D channel to set up

calls, disconnect calls etc. Found in Blue book Fascicle VI.11

Q.930: General Overview

Q.931: Basic ISDN call control

Q.932: Generic procedures for the control of ISDN supplementary services

Q.933: Frame Mode Call Control

Q.2931 (ex-Q.93B): B-ISDN Call control

G.711: Pulse Code Modulation (PCM) of Voice Frequencies

G.722: 7-kHz Audio Coding Within 64 kbit/s

G.728: Coding of Speech at 16 kbit/s Using Low-Delay Code Excited

Linear Prediction (LD-CELP)

H.320: Narrow-band Visual Telephone Systems and Terminal Equipment

H.221: Frame Structure for a 64 to 1920 kbit/s Channel in Audiovisual

Teleservices

H.230: Frame Synchronous Control and Indication Signals for Audiovisual Systems

H.242: System for Establishing Communications Between Audiovisual Terminals

Using Digital Channels up to 2 Mbit/s

H.261: Video Codec for Audiovisual Services at p x 64 kbits/s

H.243: Basic MCU Procedures for Establishing Communications Between Three or

More Audiovisual Terminals Using Digital Channels Up to 2 Mbit/s

I.2xy "ISDN Frame Mode Bearer Services", 1990

I.310 ISDN - Network Functional Principles

I.320 ISDN protocol reference model

I.324 ISDN Network Architecture

I.325 Reference configs for ISDN connection types

I.326

I.330 ISDN numbering and addressing principles

I.331 Numbering plan for ISDN (and several more in I.33x relating

to numbering and addressing and routing)

I.340 ISDN connection types

I.350/351/352 refer to performance objectives

I.410-412 refer to user-network interfaces

as do I.420 and 421

I.430/430 Layer 1 specs

I.440/441 Layer 2 specs (Q.921)

I.450-452 Layer 3 specs (Q.931)

I.450: General Overview

I.451: Basic ISDN call control

I.452: Extensions

I.460-465 Multiplexing and rate adaption

I.470 Relationship of terminal functions to ISDN

V.110

(aka I.463) "Support of DTE's with V Series Type Interfaces by an ISDN"

Terminal rate adaption by bit stuffing. C.f. V120.

V.120

(aka I465) "Support by an ISDN of Data Terminal Equipment with V series

Type Interfaces with Provision for Statistical Multiplexing" 1990

(This has been amended since the blue book). An alternative to

V.110

V.25bis calling mechanism under synchronous.

TSS (formerly CCITT) standards can be obtained via:

On line (anonymous ftp):

[ Ed Note: People report that these documents are missing tables

and figures. Also, these documents are in various formats:

ASCII, PostScript and Micrsoft Word 2.0. If anyone has any

further comments, let me know ]

kum.kaist.ac.kr: /doc/STANDARDS/ccitt

src.doc.ic.ac.uk: /pub/computing/ccitt/ccitt-standards/ccitt

croton.inria.fr: /ITU/ccitt

cs.huji.ac.il: /pub/doc/standards/ccitt

ftp.uu.net: /pub/lietrary/obi/Standards/CCITT

gatekeeper.dec.com:

/pub/net/info/bruno.cs.colorado.edu/pub/standards/ccitt

imag.imag.fr:/doc/ccitt

metro.ucc.su.oz.au: /pub/ccitt

quepasa.cs.tu-berlin.de: /pub/doc/CCITT

sh.wide.ad.jp:/CCITT

unix.hensa.ac.uk:/pub/uunet/doc/literary/obi/Standards/CCITT

world.std.com:/obi/Standards/CCITT

Gopher: info.itu.ch

E-Mail: Mail to: teledoc@itu.arcom.ch

Mail body:

HELP

LIST ITU

LIST ITU /REC

Hard Copy:

International Telecommunication Union

Information Services Department

Place des Nations

1211 Geneva 20

Switzerland

TEL: +41 22 730 5554

FAX: +41 22 730 5337

Internet email: helpdesk@itu.ch

X.400 email: S=helpdesk;A=arcom;P=itu;C=ch

cherkus@unimaster.com

dave@philips.oz.au

oj@vivo.com

KUMQUAT@SMCVAX.SMCVT.EDU (Gary C. Kessler)

we34329@is1.vub.ac.be (Sven De Kerpel)

---

20) Who is shipping what?

ISDN Products by Vendor:

Key:

IF: Interface Card

TA: Terminal Adapter (Standalone)

BR: Bridge

RO: Router

TE: Telephones

IC: Integrated Circuit

TS: Test Equipment

VC: Video Teleconferencing Equipment

CC: Call Control Software

Vendor Info:

Advanced Micro Devices

901 Thomson place

Mailstop 126

Sunnyvale, CA 94086

(408) 732 2400 (voice)

American Telephone and Telegraph

1-800-222-PART: Quick access to small quanity orders of ISDN products.

Personal Desktop Video or TeleMedia Connection System:

Visual Communications Products

8100 East Maplewood Avenue 1st Floor

Englewood, CO 80111

(800)843-3646 (800)VIDEO-GO Prompt 3

ANDO:

7617 Standish Place

Rockville, MD 20855

voice: (301) 294-3365

fax: (301) 294-3359

email: mgriffin@access.digex.net

Ascend Communications, Inc.

1275 Harbor Bay Pkwy

Alameda, CA 94501

(510) 769-6001

info@ascend.com

AT&T Microelectronics

Allentown, PA

(800) 372-2447

Distributer: CoSystems at 408.748.2190

mktg: Steve Martinez at 408.748.2194 (steve@cosystems.com)

tech: Gary Martin at 408.748.2195 (gary@cosystems.com)

BinTec Computersysteme GmbH

Willstaetter Str. 30

D-90449 Nuernberg

Germany

Phone: +49.911.9673-0

Fax: +49.911.6880725

email: vertrieb@bintec.de

Combinet

333 West El Camino Real, Suite 240

Sunnyvale, California 94087

(408) 522 9020 (voice)

(408) 732 5479 (fax)

CPV-Stollmann Vertriebs GmbH

Gasstrasse 18 P.O. Box 50 14 03

D-22761 Hamburg D-22714 Hamburg

Germany Germany

Phone: +49-40-890 88-0

Fax: +49-40-890 88-444

Electronic Mail:

Info@Stollmann.DE (general inquiries)

Helge.Oldach@Stollmann.DE (IPX router technical contact)

Michael.Gruen@Stollmann.DE (IP router technical contact)

DGM&S

609.866.1212

diehl isdn GmbH

Bahnhofstrasse 63

D-7250 Leonberg

Germany

Tel. 49/7152/93 29 0

Fax. 49/7152/93 29 99

email: bode@diehl.de

DigiBoard

6400 Flying Cloud Drive

Eden Prarie, MN 55344

(612) 943 9020 (voice)

(612) 643 5398 (fax)

info@digibd.com (email)

Digital Equipment Co

REO2 G/H2

DEC Park

Worton Grange

Reading

Berkshire

England

Gandalf

Cherry Hill Industrial Center

Building 9

Cherry Hill, NJ 08002

(800) GANDALF (voice)

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)

International Business Machines

(800) 426-2255

ISDN Systems Corp.

Vienna VA USA

703-883-0933

MITEL Corporation

360 Legget Drive

Kanata, Ontario, Canada

K2K 1X3

Paul Mannone or Peter Merriman

(613) 592-2122

Motorola UDS

5000 Bradford Drive

Huntsville, AL 35805

(205) 430 8000 (voice)

netCS Informationstechnik GmbH

Feuerbachstr. 47-49

12163 Berlin 41

Germany

Tele: +49.30/856 999-0

FAX: +49.30/855 52 18

E-Mail: sales@netcs.com / support@netcs.com

Network Express

Andrew Hasley Jim Hietala (West Region) Randy Sisto (East Region)

VP, Sales hietala@netcom.com randys@access.digex.net

4251 Plymouth Road 342 Lester Ct. 11566 Ivy Bush Court

Ann Arbor, MI 48105 Santa Clara, CA 95051 Reston, Virginia 22091

(313) 761-5005 (voice) Tel. 408-241-5165 Phone: (703) 264-5095

(313) 995-1114 (fax) Fax. 408-241-6246 Fax: (703) 264-5176

Network Express Incorporated (info@nei.com)

Andy Hasley, VP Sales (hasley@nei.com)

Randy Sisto, Product Manager Jim Hietala,Western Regional Manager

4251 Plymouth Road 342 Lester Court

Ann Arbor, MI 48105 Santa Clara, CA 95051

phone (313) 761-5005 phone (408) 241-5165

fax (313) 995-1114 fax (408) 241-6246

randys@nei.com hietala@netcom.com

Paxdata Networks Limited

Communications House

Frogmore Road

Hemel Hempstead

HERTS HP3 9RW

UK

0442 236336 (voice)

0442 236343 (fax)

mktg: Jim Fitzpatrick (jim@paxdata.demon.co.uk)

tech: Giles Heron (giles@paxdata.demon.co.uk)

Siemens Components Inc.

Integrated Circuit Division

2191 Laurelwood Road

Santa Clara, CA 95054-1514

(408) 980-4500

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)

Sun Microsystems Computer Company (SMCC)

Mountain View, CA

(800) USA-4SUN

Telenetworks

Lauren May

Tel: 707.778.8737

Fax: 707.778.7476

tn@well.sf.ca.us

Teleos

2 Meridian Road

Eatontown, NJ 07724

908.389.5700

Telesoft

Chris Cox

512.282.6701

Telrad Telecommunications, Inc.

135 Crossways Park Drive

Woodbury, New York 11797

(516) 921-8300

1 800 645-1350

Trillium

310.479.0500

Zydacron, Inc.

670 Commercial Street

Manchester, NH 03101

Tel: (603) 647-1000

Fax: (603) 647-9470

Many of the references, including Kessler, provide information on ISDN

equipment.

kenow@stpaul.ncr.com (TONY KENOW)

garym@netcom.com (Gary Martin)

bob_clemmons@smtp.esl.com (Bob Clemmons)

marc@dumbcat.sf.ca.us (Marco S Hyman)

dav@genisco.gtc.com (David L. Markowitz)

bear@holly.ho.att.com (James J Allen +1 908 834 1713)

giles@paxdata.demon.co.uk (Giles Heron)

---

21) How about that SPARCstation 10?

The hardware on the SS10 supports 2 B channels (64K+64K) and 1 D

channel (16K) for a grand total 144K in marketing speak. 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 (done)

ISDN Drivers on Solaris 2.1 or greater (done)

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.

This is also now available on the SPARCstation LX, and available as an

SBus card for any SBus workstation running Solaris 2.1 or later.

The current set of ISDN drivers for Solaris 2.1 or greater support

the AT&T 5ESS switch; the next release is expected to support

DMS-100 and national standard.

Get API_xtel* from sunsite.unc.edu:/pub/sun-info/white-papers for

more information on the API itself. The XTel libraries, etc., are

not bundled with either Solaris 2.x or SunLink ISDN at this time.

SunLink ISDN description (quoted from Fall/Winter '93 SunExpress catalog):

The SunLink ISDN software included in both kits is based on the international

CCITT standard, and supports the following carrier-dependent implementations:

o AT&T 5ESS (U.S.)

o France Telecom VN2 (France)

o DBT 1TR6 (Germany)

o Britsh Telecom ISDN2 (U.K.)

o NTT INS-Net 64 (Japan)

Sunlink ISDN software provides the following features:

o Transparent IP connectivity, to allow you to run most existing IP

applications, without modification, over ISDN

o Graphics User Interface (GUI)-based configuration tool, for easy

installation and administration

o Security features, including callback, calling address, and PPP

authentication password

o Inactivity timer, for transparent open/close connections

o Integrated network management with SunNetManager agent

dank@blacks.jpl.nasa.gov (Dan Kegel)

kessler@Eng.Sun.COM (Tom Kessler)

Greg.Onufer@Eng.Sun.COM

dav@genisco.gtc.com (David L. Markowitz)

---

22) How about that IBM Waverunner?

The IBM WaveRunner Digital Modem is an internal adapter for personal

computers (ISA or Microchannel) which can communicate over an ISDN

line to either ISDN destinations or analog modems and FAX machines.

WaveRunner requires ISDN Basic Rate service, an NT-1, and either

OS/2 2.1 or higher or Microsoft Windows 3.1 or higher.

WaveRunner uses AT-style commands, can be used with existing

communication application, supports V.120 encapsulation and performs

TCP/IP SLIP to Synchronous TCP/IP Translation.

The WaveRunner Hot Line at 1-919-254-ISDN is available for questions

Technical Support. For a product brochure, call 1-800-426-3395 and

request document 13403. To order, call 1-800-IBM-2YOU (1-800-426-2968)

A complete description is available via anonymous ftp:

ibminet.awdpa.ibm.com: pub/announcements/193-305

jordan@hursley.ibm.com (Rob Jordan)

lmarks@vnet.IBM.COM (Laurence V. Marks)

---

23) What is a SPID? How come my ISDN device won't work without one?

SPIDs are Service Profiles IDs. SPIDs are used to identify what sort

of services and features the switch provides to the ISDN device.

Currently they are used only for SAPI 0 (circuit-switched) service.

Annex A to ITU recommendation Q.932 specifies the (optional) procedures

for SPIDs. They are most commonly implemented by ISDN equipment used

in North America.

When a new subscriber is added, the telco personnel allocate a SPID

just as they allocate a directory number. In many cases, the SPID

number is identical to the (full ten digit) directory number. In other

cases it may be the directory number concatinated with various other

strings of digits, such as digits 0100 or 0010, 1 or 2 (indicating the

first or second B channel on a non-centrex line), or 100 or 200 (same

idea but on a centrex line) or some other, seemingly arbitrary string.

Some people report SPIDs of the form 01nnnnnnn0 for AT&T custom and

01nnnnnnn011 for NI-1, where n is the seven digit directory number.

It is all quite implementation dependent.

When the subscriber plugs in a properly configured device to the line,

Layer 2 initialization (TEI assignment) takes place, establishing the

transport mechanism. However if the subscriber has not configured the

given SPID into their ISDN device, the device should not perform layer

3 initialization and the subscriber will not be able to make calls.

This is, unfortunately, how many subscribers discover they need a

SPID.

Once the SPID is configured, the terminals go through an

initialization/identification state which has the terminal send the

SPID to the network in a Layer 3 INFOrmation message whereby the

network responds with an INFO message with the EID information element

(ie). Thereafter the SPID is not sent again to the switch. The switch

may send the EID or the Called Party Number (CdPN) in the SETUP message

to the terminal for the purpose of terminal selection.

SPIDs should not be confused with TEIs (terminal endpoint identifiers).

TEIs identify the terminal at Layer 2 for a particular interface

(line). TEIs will be unique on an interface, whereas SPIDs will be

unique on the whole switch and tend to be derived from the primary

directory number of the subscriber. Although they are used at

different layers, they have a 1-to-1 correspondence so mixing them up

isn't too dangerous. TEIs are dynamic (different each time the terminal

is plugged into the switch) but SPIDS are not. Following the

initialization sequence mentioned above the 1-to-1 correspondence is

established. TEIs are usually not visible to the ISDN user so they are

not as well known as SPIDs.

The "address" of the layer 3 message is usually considered to be the

Call Reference Value (also dynamic but this time on a per call basis)

as opposed to the SPID, so the management entity in the ISDN device's

software must associate EID/CdPN on a particular TEI and Call Reference

Number to a SPID.

There are some standards that call for a default Service Profile, where

a terminal doesn't need to provide a SPID to become active. Without

the SPID however, the switch has no way of knowing which terminal is

which on the interface so for multiple terminals an incoming call would

be offered to the first terminal that responded, rather than to a

specific terminal.

sorflet@bnr.ca (winston (w.l.) sorfleet)

cstorry@gandalf.ca (Chuck Storry)

---

24) Will ISDN terminal equipment that works in one country

work properly when it is installed in another country?

There are three major problem areas.

The first has to do with voice encoding, and is only a problem if the

equipment is a telephone. Equipment designed for use in North America

and Japan uses mu-law encoding when converting from analog to digital,

whereas the rest of the world uses A-law. If the equipment can be

switched, then there will not be a problem with the voice encoding.

The second has to do with the way the equipment communicates with the

telephone exchange. There are interoperability problems because there

are so many different services (and related parameters) that the user

can request and because each country can decide whether or not to allow

the telephone echange to offer a given service and because the

specifications that describe the services are open to interpretation in

many different ways. So, as with other interoperability problems,

you must work with the vendors to determine if the equipment will

interoperate. This is a basic problem; it impacts all ISDN

equipment, not just voice equipment.

The third has to do with homologation, or regulatory approval. In most

countries in the world the manufacturer of telephone equipment must

obtain approvals before the equipment may be connected to the network.

So, even if the equpipment works with the network in a particular

country, it isn't OK to hook it up until the manufacturer has jumped

through the various hoops to demonstrate safety and compliance. It is

typically more expensive to obtain world-wide homologation approvals

for a newly-developed piece of ISDN equipment than it is to develop it

and tool up to manufacture it.

There are attempts to remidy this situation, particularly for BRI

ISDN. In North America, the National ISDN User's Forum is coming

up with standards that increase the uniformity of ISDN services.

In Europe, a new standard called NET3 is being developed.

msun@ntmtv.com (Ming Sun)

marc@dumbcat.sf.ca.us (Marco S Hyman)

jwb@capek.rdt.monash.edu.au (Jim Breen)

keyman@Eng.Sun.COM (Dave Evans)

oj@world.std.com (Oliver Jones)

wmartin@nsa.bt.co.uk (William Martin)

--------

25) Will ISDN terminal equipment that works with one vendor's ISDN

switch work properly when it is used with another vendor's switch?

[Ed. Note: The title is edited from the previous faq to try to fit in

with the preceding question]

[Also, this seems to imply that there are only two implementations

to worry about and it is very US-centric. This section needs to be

reworked]

Before National ISDN-1 is implemented, 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)

--------

26) Do different manufacturers Terminal Adaptors interoperate when used

asynchronously?

There is a standard up to 19.2k (V.110) but above that there is no real

standard implemented. However, in practice there is a fair degree of

interoperability (even when the TA's manual tells you otherwise)

because many TAs use the same chip set (supplied by Siemens) which

happily goes up to 38.4. TAs from different suppliers that are using

the Siemens chips have a fair chance of interoperating at up to 38.4k.

wmartin@nsa.bt.co.uk (William Martin)

--------

27) Why do I get only about 19.2k throughput from my TA?

The problems in using TA's are the same as those in using fast modems.

You only get the throughput that your serial port can handle. The

serial ports of many machines struggle to receive at 19.2k. Sending

seems to be easier. Many machines that will happily chuck data at a TA

at 38.4, but choke down to around 19.2k or l ower when receiving (with

lots of retries on ZMODEM file transfer).

wmartin@nsa.bt.co.uk (William Martin)

--------

28) How long should call setup take when using a TA?

The "less than a second" call setup sometimes claimed seems to be rare.

TAs have a negotiation phase and it typically takes around 4 seconds

to get through to the remote site.

wmartin@nsa.bt.co.uk (William Martin)

--------

29) Can I get on-line National ISDN information from Bellcore?

Information about National ISDN is now available by anonymous FTP (File

Transfer Protocol) over the Internet at host "info.bellcore.com". FTP

allows the retrieval of formatted documents and software.

The rest of this document assumes that you have access to a machine

connected to the Internet that supports FTP, and that you have a system

that can print both ASCII formatted documents and PostScript formatted

documents.

The files are available in PostScript through anonymous FTP from

"info.bellcore.com" in the /pub/ISDN sub directory.

I M P O R T A N T: Many of the files are large, it is essential

that you first get the README (the upper case is important) file

for detailed information on retrieving various files associated with

documents.

The following text describes a typical anonymous FTP session:

system: ftp info.bellcore.com <enter>

Connected to info.bellcore.com.

220 info FTP server (SunOS 4.1) ready.

Name: anonymous <enter>

331 Guest login ok, send ident as password.

Password: <enter your internet login -- example: student@university.edu>

230 Guest login ok, access restrictions apply.

ftp> cd /pub/ISDN <enter>

250 CWD command successful.

ftp> mget README <enter>

mget README? yes <enter>

200 PORT command successful.

150 ASCII data connection for README (8758 bytes).

226 ASCII Transfer complete.

local: README remote: README

8943 bytes received in 0.19 seconds (46 Kbytes/s)

ftp> quit <enter>

221 Goodbye.

<enter> represents pressing the "enter" or "return" key on your

computer keyboard.

The README file is in ASCII format and may be read with most word

processors. The other files in the directory are in PostScript format

and may be downloaded as needed by using the "mget" command while in

the FTP.

You should determine your local procedure for printing PostScript

documents. For example, on many UNIX systems, PostScript files may be

printed on a PostScript printer by using the "lpr" command. A typical

Post Script print command may look like:

lpr -P<printer> -h -v <filename.ps>

where:

<printer> represents printer name accessable to your system, and

<filename.ps> represents a PostScript file.

notes:

'-h' corresponds to the option of suppressing the printing of

burst page while '-v' corresponds to the option of printing

raster image, i.e., PostScript. Please note that the printer

must support PostScript imaging model in order to print these

files.

Some systems are configured to detect PostScript formatted files

automatically, so a command to print the documents on that kind

of system is:

lpr -P<printer> <filename.ps>

If you have problems or you'd like to comment on the information

stored at this site or wish to make recommendations for future

enhancements, you can send email to:

isdn@cc.bellcore.com

Or, call the Bellcore's National ISDN Hotline: 1-800-992-ISDN

A recent visit to the system revealed the following directories:

CATALOG: NIUF (National ISDN User's Forum) catalog:

"A Catalog of National ISDN Solutions for Selected NIUF

Applications, Second Edition." [Ed: lots of big files,

but some great info - chapter 4 is hundreds of pages of

ISDN product/vendor information]

CONTACTS: List of ISDN contacts at various Regional Bell Operating

Companies

DEPLOYMENT: Currently empty but being worked on

EVENTS: Info about the "ISDN Solutions '94" event

NATIONAL_ISDN: Bellcore document SR-NWT-2006, "National ISDN"

[Ed: I couldn't get this to print - what about you?]

README: The Read Me File

TARIFF: Currently empty but being worked on

whs70@cc.bellcore.com (sohl,william h)

--------

30) Where can I read more?

"ISDN In Perspective"

Fred R. Goldstein

Addison-Wesley

ISBN 0-201-50016-7

[Ed. Note: the second edition is new...]

"ISDN: Concepts, Facilities, and Services, Second Edition"

Gary Kessler

McGraw-Hill, 1993 (2/e).

ISBN 0-07-034247-4

"Integrated Services Digital Networks: Architectures / Protocols / Standards"

Hermann J. Helgert

Addison Wesley

ISBN 0-201-52501-1

The Basic book of ISDN (second edition)

Motorola University Press

Addison-Wesley Publisching company inc.

ISBN 0-201-56374-6

A 48 pages booklet covering all basic questions on ISDN and some case

studies on the possible installation. Can be obtained freely from

Motorola sometimes.

"Sensible ISDN Data Applications"

Jeffrey Fritz

jfritz@wvnvm.wvnet.edu

West Virginia University Press

"ISDN and Broadband ISDN" (2nd edition)

William Stallings

Macmillan

ISBN 0-02-415475-X

"Networking Standards: A Guide to OSI, ISDN, LAN and MAN Standards"

William Stallings

Addison-Wesley

"A Catalog of National ISDN Solutions for Selected NIUF Applications"

North American ISDN User's Forum

(use NIUF information above or order via Bellcore, document GP-1, $43)

and/or see info on anonymous ftp to info.bellcore.com above)

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 National ISDN Specifications

SR-NWT-001953

SR-NWT-002361

SR-NWT-002120 (National ISDN-2)

US: 1-800-521-2673, other: 1-908-699-5800

Bellcore ISDN Availability Report

WR-NWT-2102 ($103)

US: 1-800-521-2673, other: 1-908-699-5800

Bellcore ISDN Deployment Data

Special Report (SR) 2102

US: 1-800-521-2673, other: 1-908-699-5800

AT&T Technical Journal special issue on ISDN

(Volume 65, Issue 1) January/February 1986

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

---

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

Lots of people, in one way or another.

"Bob Larribeau" <p00136@psilink.com>

Eric_Boll-RXNN70Q@email.sps.mot.com (Eric Boll)

Greg.Onufer@Eng.Sun.COM

Helge.Oldach@Stollmann.DE (Helge Oldach)

Jim.Rees@umich.edu (Jim Rees)

KUMQUAT@SMCVAX.SMCVT.EDU (Gary C. Kessler)

PMW1@psuvm.psu.edu (Peter M. Weiss)

SYSGAERTNER@cygnus.frm.maschinenbau.th-darmstadt.de (Mathias Gaertner)

apsteph@cs.utexas.edu (Alan Palmer Stephens)

art@acc.com (Art Berggreen)

awillis@athena.mit.edu (Albert Willis)

bernot@inf-wiss.uni-konstanz.de (Gerhard Bernot)

bharrell@garfield.catt.ncsu.edu (Ben Harrell)

blsouth!klein@gatech.edu (Michael Klein)

bob_clemmons@smtp.esl.com (Bob Clemmons)

cherkus@UniMaster.COM (Dave Cherkus)

cliff@Berkeley.EDU (Cliff Frost)

craig@aland.bbn.com (Craig Partridge)

cstorry@gandalf.ca (Chuck Storry)

curt@kcwc.com (Curt Welch)

dank@blacks.jpl.nasa.gov (Dan Kegel)

dav@genisco.gtc.com (David L. Markowitz)

dave@philips.oz.au

dem@hep.net (David E. Martin)

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)

fenton@combinet.com (Jim Fenton)

garym@netcom.com (Gary Martin)

giles@paxdata.demon.co.uk (Giles Heron)

glarson@bnr.ca (Greg Larson)

goldstein@carafe.enet.dec.com (Fred R. Goldstein)

huntting@futureworld.advtech.uswest.com (Brad Huntting)

james@kaiwan.com (James - The Keeper)

jerry@watchman.sfc.sony.com (Jerry Scharf)

jfritz@wvnvm.wvnet.edu (Jeffrey Fritz)

jhonan@kralizec.zeta.org.au (Jamie Honan)

jik@security.ov.com (Jonathan I. Kamens)

jms@romana.Tymnet.COM (Joe Smith)

jordan@hursley.ibm.com (Rob Jordan)

jwb@capek.rdt.monash.edu.au (Jim Breen)

kenow@stpaul.ncr.com (TONY KENOW)

kessler@Eng.Sun.COM (Tom Kessler)

ketil@edb.tih.no (Ketil Albertsen,TIH)

kevin@newshost.pictel.com (Kevin Davis)

kevinc@aspect.UUCP (Kevin Collins)

keyman@Eng.Sun.COM (Dave Evans)

keyman@doorway.Eng.Sun.COM (Dave Evans)

kph@cisco.com (Kevin Paul Herbert)

krowett@large.cisco.com (Kevin J. Rowett)

lmarks@vnet.ibm.com (Laurence V. Marks)

marc@dumbcat.sf.ca.us (Marco S Hyman)

marc@Synergytics.COM (Marc Evans)

mea@intgp1.att.com (Mark Anderson)

mikes2@cc.bellcore.com (Mike Souryal)

msun@ntmtv.com (Ming Sun)

muftix@junior.bintec.de (Juergen Ernst Guenther)

oj@world.std.com (Oliver Jones)

p00210@psilink.com (Gerald L. Hopkins)

paul@suite.sw.oz.au (Paul Antoine)

peter@memex.co.uk (Peter Ilieve)

pturner@eng.auburn.edu ( Patton M. Turner)

pturner@eng.auburn.edu (Patton M. Turner)

rachelw@spider.co.uk (Rachel Willmer)

randys@access.digex.net (Randolph A. Sisto)

rdavies@janus.enet.dec.com (Rob Davies)

rjl@fawlty1.eng.monash.edu.au (Russell Lang)

rogers@eplrx7.es.dupont.com (Wade T. Rogers)

ronnie@cisco.com (Ronnie B. Kon)

sanjay@media.mit.edu (Sanjay Manandhar)

scott@labtam.labtam.oz.au (Scott Colwell)

scotty@l5next.gagetalker.com (Scott Turner)

sklower@toe.CS.Berkeley.EDU (Keith Sklower)

sorflet@bnr.ca (winston (w.l.) sorfleet)

spike@coke.std.com (Joe Ilacqua)

stamp@cc.bellcore.com (stamp,scott)

tnixon@microsoft.com (Toby Nixon)

turtle@newshub.sdsu.edu (Andrew Scherpbier)

varney@ihlpf.att.com (Al Varney)

we34329@is1.vub.ac.be (Sven De Kerpel)

wb8foz@scl.cwru.edu (David Lesher)

welch@watchtower.Berkeley.EDU (Sean N. Welch)

whs70@cc.bellcore.com (sohl,william h)

wmartin@nsa.bt.co.uk (William Martin)

----

Dave Cherkus UniMaster, Inc. cherkus@unimaster.com

--

Dave Cherkus UniMaster, Inc. cherkus@unimaster.com