ISDN: A Solution in Search of a Problem

Integrated Services Digital Network (ISDN) has been termed by some cynics "a solution without a problem." It seems, though, that the problems have finally arrived, in the form of business communications needs. Associate Editor Robert Lemos takes a look at the status of ISDN in Japan, and how it can ease your personal, small-business, and workgroup networking woes.

by R. A. Lemos

Necessity is the mother of invention - or so it has been said. If this is true, though, then it is truly amazing that the whole concept of integrated services digital network (ISDN) was ever born. For over a decade, ISDN has been a solution in search of a problem, an enabling technology without a clear need. In Japan, too, there has been the added problem that NTT was a strong proponent of this network solution -- which, for many people, was enough reason to keep away. It is only today, when having a connection to the Internet is becoming a necessity for businesses, that ISDN seems to be the ideal technology.

Until recently, NTT concentrated its ISDN promotion efforts on companies that had to communicate with remote servers, or those that needed to update information from distributed sources. Considering these relatively closed markets, the telecommunications giant has been able to maintain an impressive rate of growth for ISDN.

From April, though, with Japanese Internet providers starting to offer 64K-bps dial-up access to their Internet hosts, the number of installed ISDN lines has begun to take off. With the service fees for a personal ISDN account close to those for normal analog-access accounts, ISDN Internet connections are quickly becoming the standard. This popularity sprouts not only from individuals, but from companies using an INS-Net 64 line as the first step toward connecting their LANs (local area networks) to the outside world. For both personal and business Internet users, ISDN offers the next step up, not only in connections, but also in information-systems integration.

Not a trouble-free solution

Ask a "techie" what ISDN is, and you will most likely get a hand-waving explanation. When it comes right down to it, the integrated services digital network is a concept more than anything else: the idea that, "Hey! Today's communications is really just digital data. Let's put it all on the same phone line." In the US, the fractured telecommunications market has spawned several ISDN standards and a confusing array of incompatibilities. In Japan, NTT's monopoly has at least had the benefit of allowing its proposal to became Japan's single standard: INS-Net. Yet, even in Japan, the history of ISDN has not been without problems. "The previous INS-Net was proprietary," explains Vincent Gebes, a support engineer with PSI Japan. "It didn't follow ISDN standards."

Since 1989, INS-Net service has come in two flavors, distinguishable by bandwidth: INS-Net 64 (up to 128K bps at a reasonable price) and INS-Net 1500 (up to 1.5M bps at a price geared for medium-sized and large companies). For small companies and personal use, INS-Net 64 was the affordable solution. (See the sidebar on page 40 for INS-Net 64 prices).

An INS-Net 64 connection consists of two 64K-bps digital signaling lines (called B-channels) and one 16K-bps digital control line (called a D-channel) delivered through a single twisted-pair line (such as the phone line already in your home or office). Usually, only the B-channels are used for data transfer: a subscriber can talk on the phone using one B-channel while sending a fax at the same time on the second B-channel.

This is an important point for the user: a single ISDN line always has two data channels. Even if you use only a single B-channel, the basic monthly fee for both channels still applies. To efficiently utilize an INS-Net line, the subscriber should use a method that minimizes conflicts in communications equipment usage, such as putting each of two frequently used devices on its own dedicated channel. By placing equipment on its own channel, simultaneous use of an ISDN connection becomes possible (for example, sending a fax on one channel while simultaneously receiving a data file by modem on the other).

Individual users can quickly come up with a short list of combinations for the two B-channels, such as fax and phone, fax/phone and computer, or phone and fax/modem. For business users, too, the list is generally short: a router will most likely use one B-channel, leaving the other unassigned. But since the phone system and faxes are on a PBX (private branch exchange) network, adding a phone or fax to the INS-Net line becomes redundant.

However, more and more companies not only want to connect to the Internet, but also to a second LAN (in a customer or distributor's office, for example) or to a remote database. Having two available connections adds a great deal of flexibility to the company's LAN -- which is ISDN's primary value.

The ISDN solution is not problem-free, however. Unfortunately, as in the US, Japan's INS-Net system lacks standardization among equipment providers. Like the situation that afflicted PCMCIA cards, just because there is a standard doesn't guarantee that the interfaces between hardware components are compatible. The blame for this can be placed squarely on the back of NTT, but NTT blithely shifts the responsibility for ensuring compatibility onto the shoulders of the user. If you are considering an ISDN line, the best way to ensure compatibility between the Internet provider's equipment and your own is to start your search from the Internet provider and move backwards.

The Internet and ISDN

The face of the Internet has been quickly changing in Japan, even before a broad pool of users arrives to judge the changes in direction. The move toward ISDN, although started in the US, will probably proceed faster in Japan, where interoperability issues are less of a problem and ISDN rates are actually lower than in some other countries.

However, while interoperability issues are less of a problem in Japan, the road is not entirely free of potholes. It is still wise to start your migration to INS-Net by calling your current Internet provider and getting advice from them. (Or, if you are not already signed up with a provider, pick one from the short list given on page 40.)

Today, most personal accounts essentially connect your personal computer to the Internet service provider's host. Internet providers obtain a number of Internet Protocol (IP) addresses, which they then can assign to users. When a user connects to the host via a SLIP (serial line Internet protocol) or PPP (point-to-point protocol) account, the host dynamically assigns the user's machine one of its IP addresses. This, for all intents and purposes, puts that user's machine "on the Internet."

Most Internet providers in Japan presently offer two types of accounts that use this mechanism: analog (up to 28.8K bps) and digital (38.4K bps and 64K bps). Some providers charge identical amounts for analog access and digital access (such as PSI Japan, whose three-tiered pricing structure starts at ¥3,000 for 10 hours/month). Others charge a somewhat higher fee for a digital connection. The move to flat-rate fees for individuals has made an appearance in Japan's ISDN market, with Global OnLine Japan charging a ¥40,000 per year fixed-rate for 38.4K-bps access and ¥70,000 per year for up to 40 hours per month of 64K-bps access (with extra time charged at ¥15/minute).

Dial-up ISDN lines for businesses are based on different models. Normally, the company or workgroup LAN will maintain user accounts on a single office server or through a collaborative environment based on a peer-to-peer network. The INS-Net 64 router would have its own IP address and act as a hub to send packets to up to two locations simultaneously (remember: there are 2 B-channels). Thus, for example, several users on the LAN could be connected to the Internet provider's host while other users were accessing a remote database system at the same time. The resulting network is a cost-effective way to promote connectivity.

ISDN hardware

Start-up costs can be high. One of the main obstacles to implementing an ISDN solution is the cost of the necessary equipment. At a bare minimum, an office will usually need a terminal adapter (TA) and a digital service unit (DSU) to connect the office's currently used equipment to the INS-Net. The only way to avoid using a TA is to instead purchase INS-Net-compatible equipment (phones, faxes, PBXes, and bridges/routers) -- an alternative that, at today's prices, can be even more expensive.

The personal ISDN solution

The main benefits of a personal ISDN solution are faster Internet access speeds and the convenience of being able to get online while simultaneously calling or faxing. However, starting on the path to ISDN requires determination and a clear need: with a starting cost of over ¥150,000 for a basic ISDN package, only those who thrive online may find the solution worth the price. Once installed, though, the costs are quite reasonable for Japan, and this is what may eventually drive the market.

The first step is to talk to your Internet provider. Your choice of Internet provider will affect the answer to many other questions. Most providers have a usage-based time band in which they are most cost-efficient (for example, for under 10 hours per month, PSI Japan is a better deal than an unlimited usage, fixed-rate provider). A good strategy would be to estimate your usage and select a provider with a good cost-per-usage ratio at that level.

Also, verify the provider's bandwidth and number of users. As users demand more bandwidth, lines will start becoming more crowded. If a provider's upstream bandwidth is only 128K bps, 20 users using 64K-bps modems at the same time will not receive data any faster than 20 users using 14.4K-bps connections. Make sure your questions are answered to your satisfaction, so problems don't crop up later. Also, find out what terminal adapters (TAs) and ISDN boards will work with the Internet provider's equipment. If the provider can't answer this, don't take the risk. While there is a single standard for ISDN in Japan, there are several data communications standards, and variations within each.

If you don't mind running at 38.4K bps (several cheap services are available), a board is not required. You can just connect the TA to your computer's RS-232C port. To reach full 64K-bps communications, though, a board is necessary to output a synchronous signal. (The RS-232C port uses an asynchronous protocol.) While the board bypasses the TA, other equipment (such as a fax) will require the little black box.

To benefit the most from your step into the information era, identify what items of communications equipment (phone, fax, or computer) will most likely be used simultaneously. These should be put on separate B-channels. For most individual users, a computer and fax might be placed on one channel, and a phone on the other. Some users, though, may want the phone and fax on the same line and the computer on the other. The aim is to reduce usage conflicts by putting frequently used machines on separate lines. With these considerations, and a bit of initial investment, a personal ISDN solution can be friendly and affordable.

ISDN for business communications

Dial-up ISDN is a solution for small or mid-sized companies that want to take an initial step toward putting their LAN on the Internet, but which lack the need of larger companies to have a leased-line connection. The main difference between the personal and business ISDN solution is that, for businesses and workgroups, the dial-up ISDN connection will be dedicated to the LAN; phones and faxes would most likely be on an office PBX circuit. Thus, the ISDN connection should be optimized for computer communications.

The first step is to talk to your Internet provider and check out what the various services cost, and what equipment is compatible with their system. Several providers offer an ISDN package for businesses; PSI Japan's LAN ISDN service, for example, costs ¥120,000 per month for a dial-up 64K-bps connection, a domain name, and other related services. Other providers can put together a package on the spot (consisting of a domain name, an IP address, and unlimited 64K-bps access); Cyber Technologies, Inc., offers such a package for ¥160,000 per month. Usually, the providers will also recommend routers that have been tested with their systems.

On the LAN side, there are two important considerations: your network software, and the ability to make full use of the
two B-channels. One advantage of Internet access is electronic mail. Many networks in Japan are created just to support intra-office mail, yet the network applications that manage various aspects of these networks (NetWare, Windows NT, Microsoft Mail, Lotus Notes, and cc:Mail) are usually scaleable and have Internet gateways. Sending e-mail outside the company should be as easy as attaching the router to the workgroup server and changing some preferences. Despite some problems with the Japanese version of NetWare, downloading USENET news and connecting to the World Wide Web (WWW) should also be easy.

Use of the second B-channel may require some thought. The Internet and ISDN have not developed far enough in Japan for manufacturers and service providers to have created 128K-bps services using both B-channels. Thus, most businesses will have to look for another application: a connection to a remote LAN or database, or an independent connection to an "express" terminal dedicated to WWW use, for example. The goal is to maximize usage of the channels while minimizing connection time.

Along these lines, a workgroup policy should be developed to make efficient use of remote resources. Having several users on a single channel simultaneously will maximize channel use and minimize phone charges.

How much
does it cost?

Integrated services digital network (ISDN) has been an enigma to consumers and information managers alike. As with much new technology, the benefits have been hidden by a fog of alphabet soup: B- and D-channels, DSUs, TAs, and PSTN. In addition, Japan's system of charges has confused many people. Yet, in reality, the system is fairly simple.

For a fairly low cost, your existing phone line can be upgraded to an INS-Net circuit. For installation, the entire price should be less than ¥30,000. If a new line is necessary, NTT's standard line charge of ¥72,000 will apply. Beyond that are equipment costs: buying a digital services unit will tack another ¥23,900 to the price, while a terminal adapter will cost another ¥50,000 or more. In total, then, for basic INS-Net set-up, a potential user is looking at a minimum of ¥80,000 (if the line is upgraded and the DSU is rented), up to a maximum of ¥180,000 or more.

Yet, when you consider the improved services, monthly charges (which are set at the same base rate as a standard analog line) are quite reasonable -- for Japan, anyway. The only caveat is that instead of paying for a single line, the user must now pay for the two B-channels. This leaves a subscriber's basic phone bill twice as high, since each B-channel is charged as a separate line. (In other words, aside from the convenience, the user derives no benefit from using both lines simultaneously). Yet, if faster access to the Internet will cut down the amount of time online, the extra charge can easily pay for itself every month.

ISDN-related contacts

NTT, Network Services Dept. 03-3509-8787


Cyber Technologies, Inc. 03-3226-0961

Global OnLine, Japan 03-5330-9380

Internet Initiative Japan 03-5276-6240

NEC, C&C 03-3798-6086

Network Information Service 03-5634-3222

NTT PC Communications 03-3432-4588

PSI Japan 03-5478-7537

TWICS 03-3351-5977

INS-Net 64 communication-board makers

BUG (PC card INS-Net interface,
external ISDN modem) 03-3486-6710

CSS (Mac-compatible boards) 03-3979-8123

Elmic Systems (IBM- and NEC-compatible
boards, PC cards) 045-664-5171

Mytek (IBM-, NEC-, and PC-card-compatible
boards) 03-5609-9810

NEC (IBM- and NEC-compatible boards,
PC cards) 0120-36-1138

NTT-IT (IBM- and NEC-compatible boards) 045-651-7512

INS-Net 64 bridges/routers

Ascend 03-5322-2850

BUG (multi-protocol router) 03-3486-6710

SBE (NTT-IT) 045-651-7512