Take a second look at ISDN - ISDN solutions for small businesses - Technology Information

The Internet and internetworking have been credited with leveling the playing field and making small businesses more competitive with larger corporations. Until recently, however, large corporations still had the edge when it came to fast, reliable access -- the cost and complexity of leased line connectivity kept these benefits out of reach for small businesses and remote offices. Now integrated services digital network (ISDN) is changing this.

There are more than 23 million small-office businesses and 24 million self-employed home-based workers. Infonetics Research (San Jose, Calif.) reports that 21% of small office businesses are remotely networked, mostly with analog modems, and nearly all of them use the Internet. Many also use modems for remote access.

As office workers and telecommuters send and receive more image-enhanced documents, multimedia files and graphics, they are increasingly less satisfied with the slow transfer rates of their analog modems.

Because small business owners rarely have the time to research Internet technology, integration, or remote access, they represent a ready market for network vendors who can help them cost-effectively increase their productivity while expanding their competitiveness and geographic reach.

ISDN service replaces dialed analog connections with a multichannel, dial-up digital technology that is routed through standard telephone wires.

Basic-rate interface (BRI) ISDN consists of two 64 Kbps B-channels (bearer channels) that carry the user's voice, data, image, and sound traffic in both directions and one 16 Kbps D-channel (data channel) that carries the call set-up and signaling information.

The bearer channel is capable of transmitting data at 64 Kbps using switched digital connections. For higher system throughput, two bearer channels can be bundled together to increase transmitting speed to 128 Kbps using a standard called Multilink PPP.

By using two bearer channels in a BRI, the user can have at least three applications (PC, phone, fax) using the same telephone line, with each application running independently. Aggregate BRI lines can also be used at the company's corporate office to handle incoming traffic.

The key benefits of an ISDN connection to the Internet are speed and reliability. ISDN is up to four times faster than a 28.8 Kbps modem, and connect times are also faster. Call establishment times average one-tenth of a second, compared to approximately 25 seconds for an analog modem, and there is no modulation protocol handshaking period as there is with analog modems.

With faster access and higher throughput, users spend less time connecting, searching and downloading information. which also reduces line charges. In many cases, you can replace two analog telephone lines with one ISDN line for additional savings.

The cost of an ISDN line varies widely nationwide, but is usually lower than or equal to the price of two analog lines. ISDN can also be used for voice and data simultaneously, so you can make a phone call or receive a fax while files download.

ISDN's end-to-end digital transmission virtually eliminates line noise. Line noise not only slows transmission in analog, dial-up solutions, but it also can cause dropped connections and higher data error rates.

AT&T estimates that a regular plain old telephone service (POTS) line has a reliability rating of 75%, while a digital connection is close to 100%. ISDN error-checking is done in the hardware, so no bandwidth is lost to error-correction protocols.

When it emerged in the 1980s, ISDN was available on a limited basis. With the growing demand for low-cost, high-speed access, however, telcos in the U.S. have reinforced their commitment to ISDN by investing millions of dollars to expand its availability.

The U.S. National ISDN-1 standard is now available on more than 90 million circuits, and most major metropolitan areas and central offices are 100% ready (see map).

Early ISDN users had to deal with complicated ordering procedures, equipment installation, and configuration challenges. During the past year, telcos have become more responsive to customer demands for ISDN service, and ISDN equipment manufacturers have unveiled products that are as easy to install and use as a modem.

When asked what they like most about ISDN, most users say it's the ability to select the level of bandwidth so they only pay for what they need when they need it. Used primarily as a tool for Internet and Web access as well as for file transfers, BRI ISDN is also an ideal solution for providing branch offices and telecommuters with fast access to a corporate network or database.

Since remote users usually don't require a permanent connection to corporate headquarters, leased line or permanent virtual circuits (PVCs) aren't cost-effective. In fact, when network managers analyze their voice, data and video traffic closely, they often find that the leased lines are not being used and that their bursty traffic could be better served by the bandwidth-on-demand capabilities of ISDN.

ISDN routers that provide bandwidth on demand sense how much bandwidth is being used, add connections during times of high traffic, and break connections as traffic subsides. The savings in line can be substantial.

With dial-on-demand capabilities, routers can also automatically establish an ISDN connection when network packets are routed to a remote site. Some routers even allow connections to be scheduled for off-peak hours, when phone rates are more economical.

The bandwidth-on-demand and dial-on-demand capabilities provided by ISDN also make it a convenient and cost-effective backup to leased lines in the event of line failure, or as a means of providing additional bandwidth when the main link is overflowing with traffic.

A dedicated 64 Kbps ISDN connection can often deliver better performance than a congested T1 (1.544 Mbps) connection.

Once an organization has justified the need for faster access to the Internet and remote offices, the choice is between T1 and ISDN. ISDN connection and installation fees vary widely, depending on where you live. Start-up fees range from $65 in Denver to $400 in Texas. Monthly fees range from $30 to nearly $100. Line fees are generally a few cents per minute. Even the highest-priced ISDN connection is still considerably less than a T1 connection.

Unlike other options, ISDN is designed as an any-to-any switched network service that can support many types of applications. While remote network access, telecommuting, and high-speed Internet access are fueling the ISDN market today, only ISDN was designed to allow logical integration of voice and data into the same application using a common set of standard protocols. ISDN also provides access to future broadband services.

Now that there is widespread availability and installation/management has been simplified, ISDN is the best choice for fast, reliable connection to the Internet and remote offices. And, from the size of the investments telcos have made in ISDN, they expect ISDN to be around for a long time.

COPYRIGHT 1998 Nelson Publishing
COPYRIGHT 2000 Gale Group