36 Isdn Theory

8/3/2019 36 Isdn Theory

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MODEL ISDN100

ISDN TRAINER

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INTRODUCTION

This trainer provides training of hardware and software theory of ISDN technology with 25 experiments.

SPECIFICATION

(A) Computer Systems (2 Nos.)

1. CPU with fan : Intel Pentium IV 1.5 GHz

2. Mother Board : 200 MHZ FSB

3. Memory (RAM) : 128 MB SDRAM

4. Display Adaptor card : On Board AGP 8 MB

5. Hard Disk : 40 GB ATA

6. Floppy Disk Drive : 1.44 MB

7. Monitor : 15" Colour SVGA

8. Key board : 104 Keys Keyboard

9. Mouse : Logitech 1st Mouse with pad

10. SMPS : 200 Watts AT

(B) ISDN Hardware

1. Analog Telephones : 2 No.

2. Web Cam Camera : 2 No.

3. ISDN Emulator : 1 No.

(C) Training Packages

1. ISDN Training software

(D) Two no. of ISDN lines are required for experiments.


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Integrated services digital network (ISDN)

A generic term referring to the integration of communications services transported over digital facilities such as wire pairs, coaxial cables, optical fibers, microwave radio, and satellites. ISDN provides end-to-end digital connectivity between any two (or more) communications devices. Information enters, passes through, and exits the network in acompletely digital fashion.

Since the introduction of pulse-code-modulation (PCM) transmission in 1962, the worldwide communications system hasbeen evolving toward use of the most advanced digital technology for both voice and non-voice applications. Pulse codemodulation is a sampling technique which transforms a voice signal with a bandwidth of 4 kHz into a digital bit stream,usually of 64 kilobits per second (kbps)..

Many aspects of telecommunications are improved with digital technology. For example, digital technology lends itself tovery large-scale integration (VLSI) technology and its associated benefits of miniaturization and cost reduction. Inaddition, computers operate digitally. Digital transport provides for human-to-human, computer-to-computer, and human-to-computer interactions. The ISDN is capable of transporting voice, data, graphics, text, and even video information overthe same equipment.

The customer has access to a wide spectrum of communications services by way of a single access link. This is in contrasto existing methods of service access, which segregate services into specialized lines.

Associated with integrated access and ISDN is the concept of a standard interface. The objective of a standard interface isto allow any ISDN terminal to be plugged into any ISDN interface, resulting in terminal portability, flexibility, and ease inoperation.

ISDN

(Integrated Services Digital Network) An international standard for switched, digital dial-up telephone service for voiceand data. Analog telephones and fax machines are used over ISDN lines, but their signals are converted into digital by theISDN terminal adapter (see below).

Although announced in the early 1980s, it took more than a decade before ISDN became widely available. It enjoyed asurge of growth in the early days of the Internet, because it provided the only higher-speed alternative to analog modemsin many areas. Still working in many behind-the-scenes applications, ISDN is rarely used for Internet access.

Channels

ISDN uses 64 Kbps "B" (bearer) channels to carry voice and data. A separate "D" (delta) channel is used for control. TheD channel signals the carrier's voice switch to make calls, put them on hold and activate features such as conferencecalling and call forwarding. It also receives caller ID data. Because the D channel connects directly to the telephonesystem's SS7 signaling network, ISDN calls are dialed much faster than regular telephone calls.

Basic Service

ISDN BRI (Basic Rate Interface) uses one wire pair to carry two 64 Kbps B channels and one 16 Kbps D channel (2B+D)Both B channels are often "bonded" into one, providing a total data rate of 128 Kbps.


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High-Speed Service

ISDN PRI (Primary Rate Interface) uses four wire pairs to provide 23 B channels and one 64 Kbps D channel (23B+D). APRI line is equivalent to a 24-channel T1 line. Bonding channels is common; for example, six channels provide 384 Kbpsfor high-quality videoconferencing. In Europe, PRI includes 30 B channels and one D channel, equivalent to an E1 line.

Connecting to ISDN

ISDN requires a network terminator (NT1) and terminal adapter (TA). The NT1 plugs into the two-wire line from thetelephone company and provides four-wire output to the terminal adapter. In the U.S., the NT1 and TA are typicallycombined in one unit, but are separate in Europe and Japan.

The terminal adapter is called an "ISDN modem" if it has a built-in analog modem to hook up regular telephones and faxmachines. If the ISP supports the Multi link PPP (MPPP) protocol, the TA can bond channels for faster Internet access.


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Typical SOHO Installation

An ISDN terminal adapter with phone support (ISDNmodem) allows a telephone, fax machine and PC tocommunicate via the ISDN service.


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Typical LAN Installation

LANs typically connect to ISDN via a router, which enablesmultiple users to share the available channels. For Internetaccess, the router supplies temporary IP addresses to each ofthe nodes. Routers may also provide analog phone support.

ISDN (Integrated Services Digital Network)

International network for transmitting voice, video, or data over digital phone lines, without a modem. ISDN systems canbe used to transmit radio advertisements to multiple stations.

Integrated Services Digital Network (ISDN)

A telecommunications technology offered by telephone companies that allows for the rapid (128Kbps) transfer of voiceand data. Communication is digital, in contrast to the analog telephone system, and requires use of a network terminatorand an ISDN adapter, sometimes referred to as a digital modem.

ISDN

Digital telecommunications network that operates over standard copper telephone wires or other media. ISDN connectionsare used to provide a variety of digital services to customers, including digital voice telephone, fax, e-mail, digital videoand access to the Internet. A wide range of data transfer rates are available, with speeds up to about 128 kilobits persecond (kbps). ISDN is faster than an ordinary dial-up connection (at about 56 kbps), but much slower than cable modemor DSL connections (which typically exceed one megabit per second).


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ISDN is short for:

Meaning Category

I See Dollars Now Miscellaneous->Funnies

I Stil l Don't No Miscellaneous->Funnies

Inas Schule der Doppelten Negation International->German

Integrated Services Digital Network

Governmental->MilitaryComputing->NetworkingAcademic & Science->ElectronicsComputing->GeneralComputing->Drivers

It Stil l Does Nothing Miscellaneous->Funnies

Integrated Services Digital Network

Please wikify (format) this article or section as suggested in the Guide to layout and the Manual of Style.

Remove this template after wikifying. This article has been tagged since August 2006.

Integrated Services Digital Network(ISDN) is a type of circuit switched telephone network system, designed to allowdigital transmission of voice and data over ordinary telephone copper wires, resulting in better quality and higher speedsthan available with analog systems. More broadly, ISDN is a set of protocols for establishing and breaking circuitswitched connections, and for advanced call features for the user. The English term is a "backronym", thought better forEnglish-language advertisements than the original, "Integriertes Sprach- und Datennetz" (German for "Integrated Speechand Data Net").

In a videoconference, ISDN provides simultaneous voice, video, and text transmission between individual desktopvideoconferencing systems and group (room) videoconferencing systems.

In the phrase "Integrated Services Digital Network",

Integrated Services refers to ISDN's ability to deliver at minimum two simultaneous connectionsin any combination of data, voice, video, and fax, over a single line. Multiple devices can beattached to the line, and used as needed. That means an ISDN line can take care of most people'scomplete communications needs, without forcing the purchase of multiple analog phone lines at amuch higher transmission rate.

Digital refers to its purely digital transmission, as opposed to the analog transmission of plainold telephone service. If you're using an analog telephone modem for Internet access at thismoment, your Internet service provider's modem has converted this site's digital content to analogsignals before sending it to you, and your modem converts those signals back to digital whenreceiving (the same thing happens with every keystroke and mouse click you transmit). When youconnect with ISDN, there is no analog conversion. ISDN transmits data digitally, resulting in avery clear transmission quality. There is none of the static and noise of analog transmissions thatcan slow transmission speed.

Network refers to the fact that ISDN is not simply a point-to-point solution like a leased line.ISDN networks extend from the local telephone exchange to the remote user and include all ofthe telecommunications and switching equipment in between.


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Configurations

In ISDN, there are two types of channels,B (for "Bearer") andD (for "Delta").B channels are used for data (which mayinclude voice), andD channels are intended for signalling and control (but can also be used for data).

There are three ISDN implementations. Basic rate interface (BRI) also Basic rate access (BRA) consists of two Bchannels, each with bandwidth of 64 kbit/s, and one D channel with a bandwidth of 16 kbit/s. Together these three

channels can be designated as 2B+D. Primary rate interface (PRI) also Primary rate access (PRA) contains agreater number of B channels and a D channel with a bandwidth of 64 kbit/s. The number of B channels for PRI variesaccording to the nation: in North America and Japan it is 23B+1D, with an aggregate bit rate of 1.544 Mbit/s (T1); inEurope and Australia it is 30B+1D, with an aggregate bit rate of 2.048 Mbit/s (E1). Broadband Integrated Services DigitaNetwork (BISDN) is another ISDN implementation and it is able to manage different types of services at the same time. Itis primarily used within network backbones and employs ATM.

Another alternative ISDN configuration can be used in which the B channels of an ISDN basic rate interface are bondedto provide a total duplex bandwidth of 128 kbit/s. This precludes use of the line for voice calls while the internetconnection is in use.

Using bipolar with eight-zero substitution encoding technique, call data is transmitted over the data (B) channels, with thesignaling (D) channels used for call setup and management. Once a call is set up, there is a simple 64 kbit/s synchronousbi-directional data channel between the end parties, lasting until the call is terminated. There can be as many calls as thereare data channels, to the same or different end-points. Bearer channels may also be multiplexed into what may beconsidered single, higher-bandwidth channels via a process called B channel bonding.

The D channel can also be used for sending and receiving X.25 data packets, and connection to X.25 packet network, thisis specified in X.31. In practice, X.31 was only commercially implemented in France and Japan.

Reference points

A set of reference points are defined in the ISDN standard to refer to certain points between the telco and the end user

ISDN equipment.

R - defines the point between a non-ISDN device and a terminal adapter (TA) which providestranslation to and from such a device

S - defines the point between the ISDN equipment (or TA) and a Network Termination Type 2(NT-2) device

T - defines the point between the NT-2 and NT-1 devices1

U - defines the point between the NT-1 and the telco switch 2

1 Most NT-1 devices can perform the functions of the NT-2 as well, and so the S and T reference points are generally

collapsed into the S/T reference point.

2

Inside North America, the NT-1 device is considered customer premises equipment and must be maintained by thecustomer, thus, the U interface is provided to the customer. In other locations, the NT-1 device is maintained by the telco,

and the S/T interface is provided to the customer.


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Types of communications handled

Among the kinds of data that can be moved over the 64 kbit/s channels are pulse-code modulated voice calls, providingaccess to the traditional voice PSTN. This information can be passed between the network and the user end-point at callset-up time. In North America, ISDN is now used mostly as an alternative to analog connections, most commonly for

Internet access. Some of the services envisioned as being delivered over ISDN are now delivered over the Internet insteadIn Europe, and in Germany in particular, ISDN has been successfully marketed as a phone with features, as opposed to aPOTS phone (Plain Old Telephone Service) with few or no features. Meanwhile, features that were first available withISDN (such as Three-Way Call, Call Forwarding, Caller ID, etc.) are now commonly available for ordinary analog phonesas well, eliminating this advantage of ISDN. Another advantage of ISDN was the possibility of multiple simultaneouscalls (one call per B channel), e.g. for big families, but with the increased popularity and reduced prices of mobiletelephony this has become less interesting as well, making ISDN unappealing to the private customer. However, ISDN istypically more reliable than POTS, and has a significantly faster call setup time compared with POTS, and IP connectionsover ISDN typically have some 30-35ms round trip time, as opposed to 120-180ms (both measured with otherwise unusedlines) over 56k or V.34 modems, making ISDN more pleasant for telecommuters.

Where an analog connection requires a modem, an ISDN connection requires a terminal adapter (TA). The function of an

ISDN terminal adapter is often delivered in the form of a PC card with an S/T interface, and single-chip solutions seem toexist, considering the plethora of combined ISDN- and ADSL-routers.

A sample ISDN call

The following is an example of a Primary Rate (PRI) ISDN call showing the Q.921/LAPD and the Q.931/Networkmessage intermixed (i.e. exactly what was exchanged on the D-channel). The call is originating from the switch where thetrace was taken and goes out to some other switch, possibly an end-office LEC, who terminates the call.

The first line format is . If the message is anISDN level message, then a decoding of the message is attempted showing the various Information Elements that make upthe message. All ISDN messages are tagged with an ID number relative to the switch that started the call (local/remote)Following this optional decoding is a dump of the bytes of the message in ... ... format.


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The RRmessages at the beginning prior to the call are the keep alive messages. Then you will see a SETUP message that starts thecall. Each message is acknowledged by the other side with a RR.

10:49:47.33 21/1/24 R RR0000 02 01 01 a5 ....

10:49:47.34 21/1/24 T RR0000 02 01 01 b9 ....

10:50:17.57 21/1/24 R RR0000 02 01 01 a5 ....

10:50:17.58 21/1/24 T RR0000 02 01 01 b9 ....

10:50:24.37 21/1/24 T SETUPCall Reference : 000062-localBearer Capability : CCITT, Speech, Circuit mode, 64 kbit/sChannel ID : Implicit Interface ID implies current span, 21/1/5, ExclusiveCalling Party Number : 8018023000 National number User-provided, not screened

Presentation allowed

Called Party Number : 3739120 Type: SUBSCRB0000 00 01 a4 b8 08 02 00 3e 05 04 03 80 90 a2 18 03 .......>........0010 a9 83 85 6c 0c 21 80 38 30 31 38 30 32 33 30 30 ...l.!.8018023000020 30 70 08 c1 33 37 33 39 31 32 30 0p..3739120

10:50:24.37 21/1/24 R RR0000 00 01 01 a6 ....

10:50:24.77 21/1/24 R CALL PROCEEDINGCall Reference : 000062-localChannel ID : Implicit Interface ID implies current span, 21/1/5, Exclusive

0000 02 01 b8 a6 08 02 80 3e 02 18 03 a9 83 85 .......>......

10:50:24.77 21/1/24 T RR0000 02 01 01 ba ....

10:50:25.02 21/1/24 R ALERTINGCall Reference : 000062-localProgress Indicator : CCITT, Public network serving local user,

In-band information or an appropriate pattern is now available0000 02 01 ba a6 08 02 80 3e 01 1e 02 82 88 .......>.....

10:50:25.02 21/1/24 T RR0000 02 01 01 bc ....

10:50:28.43 21/1/24 R CONNECTCall Reference : 000062-local

0000 02 01 bc a6 08 02 80 3e 07 .......>.

10:50:28.43 21/1/24 T RR0000 02 01 01 be ....

10:50:28.43 21/1/24 T CONNECT_ACKCall Reference : 000062-local

0000 00 01 a6 be 08 02 00 3e 0f .......>.

10:50:28.44 21/1/24 R RR0000 00 01 01 a8 ....


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10:50:35.69 21/1/24 T DISCONNECT

Call Reference : 000062-localCause : 16, Normal call clearing.

0000 00 01 a8 be 08 02 00 3e 45 08 02 8a 90 .......>E....

10:50:35.70 21/1/24 R RR0000 00 01 01 aa ....

10:50:36.98 21/1/24 R RELEASECall Reference : 000062-local

0000 02 01 be aa 08 02 80 3e 4d .......>M

10:50:36.98 21/1/24 T RR0000 02 01 01 c0 ....

10:50:36.99 21/1/24 T RELEASE COMPLETECall Reference : 000062-local

0000 00 01 aa c0 08 02 00 3e 5a .......>Z

10:50:36.00 21/1/24 R RR

0000 00 01 01 ac ....

10:51:06.10 21/1/24 R RR0000 02 01 01 ad ....

10:51:06.10 21/1/24 T RR0000 02 01 01 c1 ....

10:51:36.37 21/1/24 R RR0000 02 01 01 ad ....

10:51:36.37 21/1/24 T RR0000 02 01 01 c1 ....


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Protocols

DSS1 (ETSI "Euro-ISDN", also used in many non-European countries)

DSS2 (Digital Subscriber Signaling System No. 2)

NI-1 (US National ISDN Phase 1) NI-2 (US National ISDN Phase 2)

INS-NET 64/1500 (Japanese national/NTT carrier-specific protocol)

DACS used in the UK by British Telecom it uses non standard D channel signaling for Pair gain

FTZ 1 TR 6 (obsolete German national protocol) TS.013/TS.014 (obsolete Australian national protocol)

VN2/VN3/VN4 (obsolete French national protocols)

Specifications defining the physical layer and part of the data link layers of ISDN:

ISDN BRI: ITU-T I.430. ISDN PRI: ITU-T I.431.

From the point of view of the OSI architecture, an ISDN line has a stack of three protocols

physical layer data link layer

network layer (the ISDN protocol, properly)

Other

ADSL

AT M B-ISDN Internet

H.320


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Internet access methods

Dial-up ISDN DSL Cable Wi-Fi Satellite Optical fiber Power-line Internet

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professionaleditors

Translations for: Isdn

Dansk (Danish)abbr. - Integrated Services Digital Network, tjenesteintegreret digitalnet

Nederlands (Dutch)ISDN (gentegreerde digitale netwerkdienst)

Franais (French)abbr. - RNIS, International Services Digital Network

Deutsch (German)abbr. - Integriertes Service- und Datennetz

(Greek)abbr. - (/)

Italiano (Italian)rete integrata digitale di servizi

Portugus (Portuguese)abbr. - International Services Digital Network

(Russian)

Espaol (Spanish)abbr. - RDSI red digital de servicios integrados

Svenska (Swedish)abbr. - Integrated Services Digital Network

(Arabic)()

(Hebrew)abbr. -


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QUESTIONS / ANSWERS

Question:How do I use ISDN?

Answer:

There's a lot of information published about ISDN, but much of i t is misunderstood, out of date or applies toofferings in other parts of the country. HiWAAY Internet Services is a very heavy user of ISDN and we haveestablished relationships with ISDN specialists at telcos and equipment manufacturers. This is a FAQ (FrequentlyAsked Questions) to help pass along the information we have learned about ISDN as it relates to personalInternet connectivity in Alabama. For information regarding use of ISDN in dedicated network peerinapplications please contact HiWAAY's sales department.

Q What is ISDN?

A The telephone company offers a type of telephone line connection to something called the Integrated ServicesDigital Network (ISDN). It 's called integrated because it works with the familiar analog voice telephone networkAn ISDN line uses the same single pair of twisted copper wires as an ordinary voice telephone line, and is

compatible with existing telephone wiring. However, ISDN is not compatible with standard telephones because ittransmits a high speed stream of digital data bits rather than analog voice. The entire stream of data on the ISDNline is logically divided into two separate streams of data called B channels and one stream of signaling andcontrol information called the D channel. This type of telephone service is termed a 2B+D Basic Rate Interface(BRI) l ine. In addition to digital data calls, ISDN lines can also carry voice calls as well .

Q What data rates are possible over ISDN?

A The data rate for a single B channel is 64kbps (about 64,000 bits per second) as compared to about 33.6kbpsavailable with ordinary analog voice grade lines. The 64kbps data rate for ISDN is typical, while 33.6kbps foranalog voice is rarely ever sustained in practice. In some parts of the country ISDN is not fully supported by thelocal telephone company or by particular long distance carriers. In this case an ISDN call might be routedthrough older telephone equipment that can slow down the communications rate to 56kbps. Newer telephone

equipment offers what is known as "clear channel" service, passing a full 64kbps. Most exchanges in Alabamacan provide clear channel ISDN service, thus callers can expect a full sustained 64kbps data rate on each Bchannel. Two B channels can be bonded together to offer 128kbps data rates over a single BRI. Note also that allthese are raw data rates without compression, if the terminal adapter or computer supports data compression theeffective throughput can be much higher.

Q Why use ISDN?

A ISDN lines are much faster and higher quality than analog voice grade lines. For example, to transfer a 1Mbfile (about the contents of a single computer diskette) with an ordinary 14.4kbps analog modem takes at least 12minutes and to transfer the same file over a digital ISDN line takes less than 3 minutes at 64kbps or about 1minute at 128kbps. The digital ISDN line is virtually error free, but the analog modem will usually experience

significant data errors during the transfer. While the data errors will be detected and corrected by the equipmentand software, the errors will slow the transfer of data over analog modems even further. The most noticeablebenefit of ISDN speeds is observed when using interactive Internet applications like world wide web browsersISDN speeds also make acceptable quality real-time video and audio over the Internet a reality.

Q What kind of modem is needed with ISDN lines?

A An ordinary analog modem will not work when connected directly to an ISDN line. Because there is no analogto digital modulation/demodulation required to transmit data, the communications equipment is not usually calleda modem. The proper terminology is "ISDN Terminal Adapter". The terminal adapter we recommend for


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individual use looks very much like an external modem, with a connector for power, 25 pin connector for serialdata, and a jack for the ISDN line. Terminal adapters suitable for network use also have an Ethernet port. Manyterminal adapters provide standard analog telephone interface jacks, often called POTS ports (Plain OldTelephone Service), to support ordinary voice calls over ISDN B channels. It is possible to connect an ordinaryanalog modem to one of the POTS ports on the an ISDN terminal adapter and then use the analog modem over anISDN line.

Q Does ISDN allow the computer to be on-line AND receive a voice call at the same time?

A Absolutely. Each of the two B Channels in a BRI can originate and receive completely separate calls at thesame time. A data call on one B channel can be dialed up to HiWAAY, while the other B channel receives a voicecall that is answered by a fax machine. Using one BRI line we had two file transfers running at the same time onthe same computer with two different hosts, one download from HiWAAY over a data call and the otherdownload from CompuServe using an analog modem connected to the terminal adapter POTS port. CompuServewas costing a lot of money, so we logged off and used the voice line to order a pizza while we were surfing thenet on HiWAAY.

Q Can I replace an existing analog voice l ine with an ISDN line?

A A second existing voice grade line for a fax machine, modem, or children's l ine is an excellent choice toconvert to an ISDN line. The existing phone number can even be transferred to one of the ISDN line B channelsHowever, the primary phone line should sti l l remain an ordinary analog voice line. This is because the standardtelephone service provided by POTS ports on terminal adapters are dependent upon the terminal adapter i tself. Ifthe power goes out or is turned off, any phones connected to the terminal adapter will stop working. Also, wehave found many terminal adapter POTS ports do not have enough output power to drive lines with severalextensions. For example, the POTS port works fine with a fax/telephone and analog modem, but won't haveenough power to ring several phones on several distant extensions as commonly found in ordinary premisetelephone wiring. On the plus side, the POTS provided by terminal adapters are high quality with very li t t le noiseand is an excellent choice for use with fax machines and high speed analog modems.

Q How fast a data communications rate do I really need?

A Compared to analog modems, we found noticeable major improvements in almost every Internet applicationwhen using a 64kbps ISDN data call to HiWAAY. With some exceptions, increasing the speed of the data call toHiWAAY to 128kbps resulted in further improvements but did not double the performance over 64K. Theimprovements were less apparent when visit ing very popular sites on the Internet that were congested or had slowlinks to the Internet backbone.

Q How do 56Kbps analog modems compare with ISDN?

A 56K technology more typically delivers around 45 Kbps downstream and 30Kbps upstream, and suffers fromvarious reliabili ty problems related to analog line quality. While ISDN recurring costs are somewhat greater thananalog, i t also supports 64Kbps full duplex virtually error free data transmission and up to 128K when two callsare bonded together. Thus we feel ISDN's digital technology is a vastly superior technology to analog 56Ktechnology.

Q Is ISDN available at my address?

A Your local telephone exchange must support ISDN in order for i t to be available. Today, most telcos now offerISDN service. Even if the exchange supports ISDN, there are some distance limitations and equipment barriersthat can prevent the phone company from providing ISDN service to some addresses within an exchange. Thetelephone company order processing center can determine if ISDN is available at a specific address. If i t is notavailable, ask to speak to a supervisor and find out the exact reason. The most common reason ISDN is notavailable is the address is more than 18,000 cable feet from the exchange office or they are served by subscriber


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line concentrator (SLC's or 'sl icks' as they are sometimes called) equipment which is not capable of supportingISDN. The 18,000 feet is a rule of thumb and by actually measuring the amount of signal loss on the line at theaddress, service may be available a greater distance from the exchange -OR- the phone company may be willingto install a "Total Reach" device (made by Huntsville 's own Adtran) to extend ISDN to the address.

Q What does the phone company charge for ISDN?

A BellSouth currently charges a rate of about $70 per month (it varies a dollar or two, depending upon the actual

service address) for residence BRI service which included 200 hours of usage and is metered thereafter. Othertelcos may offer significantly better pricing, for example New Hope currently charges about $45 per month forresidence BRI service with 250 hours of usage and metered thereafter. Brindley Mountain Telephone Companycharges about $43 for flat rate unmetered service. Also, most calling feature packages available at additionalcharge for ordinary analog lines are also available at similar prices for ISDN lines.

Q What is (was) the free ISDN installation offer?

A Periodically, the telcos offer to waive installation charges on ISDN BRI lines customers subject to somespecial conditions. Those special offers from tend to change, so you may wish to contact your telephone companyand inquire about their current incentive programs.

Q How do those prices compare with other areas?

A Nationwide, ISDN rates vary from state to state and telco to telco with a lot of different rate structures.Outside of states served by BellSouth, residential BRI rates are generally similar to the price of a standardresidence analog voice line. When comparing Alabama's residential BRI line cost (about $66) to the cost of anordinary residential phone line (about $22), residential BRI service seems very overpriced. Even when the cost ofa single BRI is compared to the service provided by two analog lines the cost sti l l seems high. By comparison,the Tennessee PSC has set the residential BRI rate similar to the price of a single voice phone line andinstallation charges are often waived. HiWAAY hopes that the elected officials of the Alabama PSC can be persuaded to reconsider ISDN pricing. To contact the Alabama Public Service Commission and express youopinion, call 1+800+392-8050 toll free.

Q How long does it take to get an ISDN line?

A In our experience installation time is similar to that of a new ordinary voice grade telephone line. The phonecompany will not accept an order for ISDN service until they check to see ISDN is available at the desiredaddress. Often, they are able to query a database and determine ISDN availability immediately. Sometimes it willtake the phone company about three to seven days to confirm that ISDN is available because they must actuallycheck their facili t ies capacity. We have observed a few cases where their databases indicated ISDN is availableat an address but when the actual installation begins they discover the database was incorrect. Once the order is placed, it will take about two or three weeks for the phone company to process the order and send an installerHiWAAY subscribers may begin connecting to us with ISDN as soon as their ISDN line is installed.

Q How well does HiWAAY support ISDN?

A HiWAAY believes ISDN is the future of data communications for the near term and most of our severalhundred incoming telephone lines are digital ISDN service. HiWAAY has the equivalent of both a modem and aterminal adapter on every line, so subscribers dial the same number regardless of call type. HiWAAY also promotes digital ISDN service because we are one of the few providers in the nation that offers individuasubscribers the same subscription rates regardless of connection speed. HiWAAY's equipment is already ISDNcapable and we have no special setup fees for ISDN communications.


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Q Does HiWAAY offer 128K ISDN service to individual subscribers?

A Individual Regular and Premium subscriber accounts may connect to HiWAAY with speeds up to 64kbps at noextra charge as part of the individual account services. Additional channels may be bonded to create a multi-channel session using either the MP+ or BACP bandwidth control protocol for $0.95 per hour per channel.HiWAAY offers the Premium PLUS account which includes the multichannel usage option at no additionalcharge. All individual accounts support multichannel usage (they differ only in how the usage is charged) and no

special configuration is required on HiWAAY's end, however the user 's terminal adapter may require specialconfigurations in order to bond a multichannel call to our equipment. In order to take full advantage of 128K,your serial port should support a sustained data throughput of 230K which may require special high performanceserial port hardware and drivers.

Q How does the ISDN terminal adapter connect to my computer?

A There are several different types of terminal adapter connectivity for individual computers. 1) A terminaladapter can offer RS-232 serial connectivity, identical to ordinary analog modems. It 's familiar, easy to configureand can communicate via your computers existing serial communications port. 2) A terminal adapter can offer anEthernet port, which is faster but requires a more difficult to configure Ethernet communications port andsoftware be installed on your computer. Just l ike modems, there are internal and external models of both these

types terminal adapters. The external models require your computer to provide the appropriate typecommunications port, while the internal models have the communications port integrated with the adapter. 3) Anew class of internal ISDN adapters for PC's are emerging that use a ISDN interface standard which has beendefined by Microsoft together with a few key ISDN product manufacturers. These combine ease of configurationand better theoretical performance, but availability is limited to a few products and specialized software isrequired from both Microsoft and the hardware vendor.

Q Which type of connectivity does HiWAAY recommend?

A For use with an individual computer, our practical experience suggests all the connectivity options actually perform about as well . Choice is more dictated by the hardware, experience and preferences of the user ratherthan any technical superiority of one type over another. Our observations have been that installing internal

versions which require substantial configuration and special software can be challenging for those who are notintimately familiar with their computer. Thus, for individual use HiWAAY currently suggests selecting anexternal model with a serial port, because they are easy to install , allow viewing of diagnostic l ights and thecomputer can be turned off while the terminal adapter can remain powered on to allow voice calls.

Q What terminal adapter does HiWAAY recommend for individual use?

A With the introduction of many ISDN terminal adapters from different manufacturers, we have begun to noticevariances in inter-operabili ty and reliabili ty among products for ISDN connectivity, thus much like modems...alterminal adapters are NOT equal. We currently recommend using an ISDN terminal adapter that connects to yourcomputer via a serial com port and which supports multichannel sessions with the MP+ protocol. Look for modelsthat state explicitly that they will connect to Ascend equipment. Many of our users have reported good resultswith the external Adtran XRT, the internal Diamond NetCommander and external versions of the 3Com (USR)Sportster ISDN and Courier I-modem terminal adapters.

Q What do I need to do to connect to HiWAAY with ISDN?

A Individual subscribers should follow the steps outlined in our information sheet t i t led "Ordering ISDN servicesin Alabama for use with HiWAAY". The steps are simple: purchase a terminal adapter, order a BRI line, instaland configure the terminal adapter and software on a personal computer and logon to HiWAAY. Nothing specialhas to be done at HiWAAY for individual subscriber accounts to connect using ISDN, ISDN connectivity isincluded at no extra charge as part of the individual account.


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Ordering ISDN Services in Alabama for Use With HiWAAY

Step 1) Determine if ISDN service is available at your address.

Contact the local telephone company (see the phone book for ordering phone number) and request ISDN service at theaddress where service is desired. They should call back in three to seven days confirming that it is available.

Step 2) When the phone company confirms ISDN is available, select and purchase your ISDN terminal adapter.

There are many good consumer terminal adapters available. HiWAAY has tested ISDN terminal adapters from AdtranDiamond, and 3Com (USR) and found them to work well.

Step 3) Place the order for your ISDN line with the telephone company.

Consult the adapter documentation regarding ISDN line configuration requirements. The following information will order

a BRI 2B+D data and voice NI-1 ISDN line, sometimes described by the telco as EZ1 ISDN service.

Basic Rate Interface (BRI) ISDN circuit with two 'B' and one 'D' channels.

C.O. service type required is National ISDN-1 (NI-1). Circuit switched data and voice (CSD/CSV) on both 'B' channels. Two Service Profile Identifiers (SPID's) are requested.

Terminal Type is A, Terminal Equipment Identifier is dynamic. Long distance carrier may be any LD carrier the subscriber prefers.

Preferred wall jack is the 8-pin RJ45, but standard RJ11 is acceptable.

As with an ordinary telephone line, standard installation provides the service to the "network interface" which usually is asmall box outside or just inside the building. You are responsible for inside or premise wiring to get the line from the

network interface to near your computer. The telephone company can do the inside wiring of the line, which includes awall outlet jack, for an additional installation charge. We recommend the RJ45 type wall jack to prevent confusing theISDN line with an ordinary line and inadvertently plugging equipment into the wrong jack, but the common RJ11 willwork as well.

Step 4) It takes about two or three weeks for your ISDN line to be installed.

When the installer arrives, confirm the order specification for the line and ask the installer to test that a 64K clear channelISDN data call can be made to the HiWAAY exchange once installation is complete. The most common installationproblems with ISDN lines are failure to configure as NI-1 (often it will be mistakenly configured as 'Custom' instead),failure to provide the correct SPID numbers, inability of the central office exchange to pass a clear channel 64K callinability of the central office to route an ISDN data call to the HiWAAY telephone number.

Step 5) Very carefully confirm each SPID number with the installer.

Each SPID will generally look something like aaannnnnnn0100 -or- 01nnnnnnn00. The aaa prefix may be our three digitarea code or the two digits 01. The nnnnnnn is the 7-digit phone number and there should be a unique phone number witheach SPID. The SPID may (or may not) include the two digit double 00 terminal identifier suffix at the end as shown inthe examples, and in some cases the terminal identifier may instead be a 01. If your SPID begins with 01 and not yourarea code, question the installer carefully regarding the configuration type; in our experience a 01 prefix usually indicatesthe line has been incorrectly configured as Custom and not National.


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Step 6) Follow the adapters installation guide to enter the SPID's and ISDN line type (NI-1).

Many models of terminal adapters require you only to enter the area code and phone numbers for the BRI line; the adapterwill 'autodetect' the actual SPID. Some terminal adapters will supply the terminal equipment identifier automatically andyou should not enter it when entering the SPID. Some adapters must have the terminal equipment identifier explicitly

entered, documentation for the adapter will indicate the proper configuration. When the adapter is properlycommunicating with the ISDN line an indicator should light. If the adapter supports voice calls, a voice phone call shouldbe possible from the telephone interface (POTS port) with an ordinary telephone. If the adapter fails to synchronize withthe BRI line, the trouble is very often that the switch type (NI-1) and/or SPID's are incorrectly configured in the adapter.

Step 7) Once the adapter is communicating with the ISDN line, install and configure the software to connect with

HiWAAY.

Configure the adapter/software to do PPP async to sync data conversion (or optionally V.120 rate adaptation) and onlyPAP authentication. Note that many adapters default to connecting at 56K rather than 64K, but HiWAAY fully supports64K so you may wish to consult your documentation to insure your adapter is configured for 64K. For single channelcalls, generally there is no need to make any special changes to the software configuration that you use to connect to

HiWAAY. However, for multichannel bonded 128K calls substantial changes to your your software or terminal adapterconfiguration may be required, consult the vendor of your terminal adapter for instructions.

Documents

36 Isdn Theory