by David Ginsberg

The popularity of the Internet and the commercial online services have been growing wildly this past year. It seems that everyone is getting "wired." As more and more people enter the online world, they are finding that their modem speed often limits the information they can download. It can take over two and one-half hours to download an 8MB movie trailer file at 14.4K! As more and more online services add graphics, sound, and even compressed video, users will find that even a 28.8K modem is not fast enough to retrieve the information that they want. What is an online information junkie to do?

Along comes ISDN to the rescue. ISDN (Integrated Services Digital Network) is a service available to most of California through your local phone company. There are many different service options, but the least expensive is the "home user" package. This service provides two data-grade lines capable of speeds of up to 64K each and allows analog voice on either circuit. So you can log-in to an online service on one channel and talk to a friend on voice with the other channel.

How it works

Think of your current telephone service as a garden hose. You have only one stream of water from the faucet. You can only use it to do one thing at a time: either water the lawn or wash the car. What if you want to do both at the same time? You can go to the hardware store and get a hose-splitter attachment. Now you have split the flow off into two streams, so you can easily wash the car as well as water the lawn at the same time. ISDN is the same basic theory. It allows you to take a single telephone line and split it to two separate services through the magic of digital technology. Instead of being limited to one conversation, you can have a voice call and a high speed data call, or two voice calls or two high speed data calls, all going on at one time! The basic ISDN telephone company to home user connection is called a Basic Rate Interface(BRI), and it is set up to have two large pipes called Bearer channels (B channels) and one small pipe called a Data channel (D channel). The B channels can be used for either voice or high speed data communication. The D channel contains all of the information the phone company needs to set-up your calls. Some higher end ISDN equipment will even allow you to use part of the D channel for "slow" speed (under 9660 Baud) data sessions.

What led to the service's establishment?

The telephone companies around the nation have been upgrading their switching centers for years. That is reason for the explosion of the number of custom calling features available like call waiting, three-way calling, call return, call block, etc. They have also been adding more and more fiber optic lines between their nodes. The weakest link in the phone system is the copper wiring to your home. ISDN allows that old single-channel cable to carry multiple channels by encoding the information digitally. A device in your home then takes the digital data and converts it to a form that can be used by your home computer or a normal telephone.

Is ISDN expensive?

Actually, in California ISDN is a great bargain. The Pacific Bell home service itself costs just $28.50 per month with a one time hook-up charge of $34.75. However, if you drop the service within two years of installation you will be billed a pro-rated $125 set-up fee. Pacific Bell charges a toll on all calls from 8-5PM weekdays, but then local calls are free. If your call is free on your regular phone line basic service, then it is covered in the ISDN flat rate fee. Other service providers in California may charge more for the service, but in most cases it is still generally a bargain.

What else do I need?

You will need two other things to make your ISDN connection work. The first is called a Network Termination 1 (NT1) device. This is a box that connects between your home and the phone company. It provides the call set-up capability and powers all of your ISDN devices on the line. You will also need a Terminal Adapter. This is simply a modem. It takes the electronic signals from your computer and translates them into a format that the phone company carries over the line. Now you are wondering how you can use the ISDN service like a regular phone as I mentioned earlier. This is possible by using special ISDN phones or your NT1 may have an adapter that will convert an analog phone into an ISDN phone by plugging into a regular modular jack. All of this hardware can get quite expensive. A plain vanilla NT-1 is about $150, and a TA can range from $450 to $1500, and we haven't even talked about getting the hardware to do voice calls yet!

Many companies are addressing the home user with all in one NT1/TA and analog phone adapter boxes. This allows you to buy one piece of hardware that can serve all of the functions you need, thus lowering manufacturing costs. One of the most reasonably priced units is the 3Com Quick Access Remote. This box has everything you need to get a Mac on ISDN. It contains the NT1, TA, a modular connector for an analog phone to plug into, a serial cable to connect the unit to the Mac, and software. Its current price is about $499 mail order. Older Macs may not have a fast enough serial port for external ISDN TAs. Those users may want to look into the NuBus board available from Euphonics called the Planet II. It is expensive and requires a separate external NT1, but it will work around your serial port bottleneck. More information on this card is available from the ISDN vendors at the end of this article.

Hook me up!

Here is where it gets complicated. First you have to decide what you want to use your new high speed data channel for. Currently, not all ISDN data devices can talk to any other ISDN device; there are still some compatibility problems. Be sure to call the service you want to connect to and ask them if their equipment will work with the hardware you want to buy. If they don't know for certain, call the manufacturer and tell them your application. They will usually know what will work with their products.

Next you have to order your ISDN phone service. This requires a call to your telephone service provider with all of the technical specifications of your NT1/TA. Remember, all ISDN hardware is different, so make sure you get a list of phone company service requirements for your box before you order your service. The phone company will then most likely send a crew out to check if your area is capable of ISDN service. There are certain technical considerations-like your distance to the switching center-that they need to take into account. Since the popularity of ISDN is rising, it may take three to five days before they get to your survey. If everything is okay, they will then call you to schedule installation.

You have a couple of options here. They can wire the service to the Point of Entry box where your normal phone service enters on the outside of your house or apartment, or you can have them run the service into a jack in your home. I would recommend that you let them run your inside wiring unless you are good with your hands and you have wired in phone jacks before. This eliminates one possible problem point in the ISDN circuit. Even if you are going to take care of the inside wiring yourself, make sure you are home when they hook you up. This is a chance to check that your line has been set-up properly and get any problems reporting numbers that you may need later. Ideally, you should have bought all of your hardware and have everything ready to go so you can check the connection with the installer still there. Be sure to check both your data and voice connections. Some phone company incompatibilities with your hardware may cause one or the other to malfunction.

Now you have to configure your NT1. You do this by telling it what your phone number and SPID (Service Provider ID number) are. For example, on the 3Com unit you would run an installer program and respond with the following for Pacific Bell:

Switch Type: AT&T 5ESS Custom

Telephone Number 1: 8185551212(the number the phone company gave you)

SPID: LEAVE BLANK (Since Pacific Bell uses point-to-point signaling)

Telephone Number 2: LEAVE BLANK

SPID #: LEAVE BLANK

and click update on the installer screen. Now turn the unit off and then on again to learn your settings.

What Now?

Okay, so you have the line and your interface all connected. What are you going to do with all of this technology? Well, you have a number of options here. You can subscribe directly to the Internet via a service provider or use Compuserve, Prodigy, or AOL via ISDN.

If you go the Internet route, you have to find a provider that offers ISDN service. Currently in Los Angeles there are six providers that offer this service.

Service                      Contact Number

Cloverleaf                   714.895.3075
DirectNet                    213.383.3144 
EarthLink                    213.644.9500 
InteleNet                    714.777.2817
Network Intensive            800.273.5600
PSI                          800.827.7482

Sit back and enjoy

The service itself is great. ISDN calls go through faster than a normal telephone call, and I always get a perfect connection. I often use the analog port on the 3Com unit to call the LAMG BBS while I am on the Internet on the other ISDN channel! With the service, you can download an 8MB file in 30 minutes, see almost instant graphics transfers in Netscape, or browse the news groups at blinding speed. Some users even drop their present analog phone service and use the second B channel as their sole voice phone line. One warning on this, unlike an analog phone, your ISDN line is not powered by the phone company. If you lose power in your home, your line will cease to function.

One final thought, if you want to jump on the ISDN train, make sure that any hardware you purchase can be upgraded to dual B channel operation. This allows you to bond the two smaller B channel pipes together to get up to a 128K connection. This is the next step for ISDN service, and you do not want to be left with obsolete hardware that does not have this capability. Although cable companies and Direct Broadcast Satellites are promising high speed Internet connections in the future, ISDN is here today, and it works. Check it out!

On the World Wide Web:

My ISDN Page (contains links to other ISDN pages and updates on this article)

ISDN Warehouse