ISDN Applications

The success and popularity of ISDN (Integrated Services Digital Network) is directly related to the remote information access market. As ISDN generates greater speed and bandwidth for users, it is able to meet the demands and then surpass expectations of the market. For most people, Internet access is the most important ISDN application. The Internet has been used to describe all levels of remote access to electronic information, such as news groups, e-mail, and the World Wide Web. The Internet has brought a bounty of information, data, and communication capabilities within everyone's grasp. Yet, most analog users are only scraping the surface. Only with digital technology can users unlock the Internet's full potential. Beyond high-speed Internet access, ISDN applications include corporate connectivity, high-speed file exchange, telecommuting, video conferencing, and transaction processing. While the major focus of these ISDN applications have been geared towards the business world, they have been gaining popularity in the small office and home office (SOHO) market. Regardless of the organization's size, ISDN integrates information technology to improve reliability, productivity, efficiency, and cost-savings.

ISDN Technology

Right now the high technology world is buzzing with excitement about ISDN. But, what is it? How can it guarantee higher speed and bandwidth than analog lines? How does it work? ISDN is an acronym for Integrated Services Digital Network. Since the 1960s, the telephone companies have been creating this network by converting their internal connections to a packet-based, digital system. Today, nearly all the voice switching within the U.S. telephone network is digital. The final connection between the telephone company's central office switch and the consumer, however, is an analog line.

With the rise in demand for computer-to-computer data communication, consumers require a network that integrates voice, data, graphic, and video services. Although analog lines offer these same services, they cannot claim the same reliability, efficiency, and capabilities of digital lines. ISDN provides clean and error-free connections that ensure secure, accurate, and stable transmissions. One digital line supports multiple devices (phone, fax, computer), integrates different types of services (voice, data, graphic, video) simultaneously, and yields faster data connections than analog lines. Plain old telephone service (POTS) lines are limited to speeds less than 53 Kbps. In contrast, digital lines do not have the same restrictions. Since ISDN lines create a direct connection between computer equipment, they can carry data at speeds up to 128 Kbps, 2.4 times faster than analog capabilities.

ISDN is revolutionary because it allows digital connectivity over the same twist-paired copper telephone line that traditionally carries analog transmissions. This means that ISDN enables an ordinary telephone line to perform with the capabilities of high-capacity and fiber-optic lines, without the cost of installing new and expensive cabling. This is made possible by a set of digital transmission protocols that establish and maintain voice, data, graphic, and video connections. ISDN transmits over two standard types of channels. The bearer channels (B channels) carry all the digital information. The data channel (D channel) transmits call setup and signaling data.

There are two standard ISDN services – Basic Rate Interface (BRI) and Primary Rate Interface (PRI). Most small businesses and home users choose the BRI service which consists of two 64 Kbps B channels and one 16 Kbps D channel (2B+D). Since each B channel is treated individually by the network, they can be used separately or bonded together. This means that users can either simultaneously connect to two different locations at 64 Kbps or connect to one place at an aggregate 128 Kbps. Typically, PRI is considered a high-level network interface. The PRI service requires two twisted paired copper telephone lines, and includes 23 64 Kbps B channels and one 64 Kbps D channel (23B+D). PRI has a total bandwidth of 1.544 Mbps and transmits through a T1 line.

ISDN and the Internet

The Internet has experienced tremendous growth in popularity. Users like the Internet because it promises colorful graphics, crisp sounds, access to data and resources, and interactive services that download with the click of a mouse. The Internet houses more than 6,000 networks and serves 250 million users. Analysts estimate that the Internet is growing at a rate of 25 percent per month. But unfortunately the Internet experience could be diminished or enhanced, depending on a user's line capabilities.

When users just want to check e-mails, join news groups, and access bulletin boards, traditional analog lines suffice. From the World Wide Web, users can tap into a wealth of information conveyed through photos, graphics, video, audio, and movies. While these types of files are very stimulating, they are extremely bloated and require wider transmission bandwidth. Users who rely on analog lines are denied the full impact of the Internet. They are forced wait patiently while their browser software slowly downloads data. Some web sites offer a text-only version, which gives the users the equivalent content but it lacks the same visual impact. To enjoy the complete effect of the Internet, users require larger bandwidth or faster speeds to download web pages. Only ISDN lines have the capabilities to give users quick access and the full features of web sites.

ISDN at the Office

ISDN is an invaluable tool for corporate America. To stay competitive, companies depend on better, faster, and cheaper communication technology. Far superior to analog lines, ISDN ensures accurate, high-speed, and efficient connectivity. With ISDN, businesses can build LAN interconnections, support telecommunting programs, conduct video conference, establish a web presence, and open a virtual store.

Whether your employees are separated by a few feet or many miles, they can still share the same resources. Creating local area networks (LANs) lowers corporate expenses and overhead by allowing workers in the same building to share equipment, information, programs, and files. Interconnecting LANs with ISDN lines increases efficiency and productivity, and reduces expenses and overhead by giving workers access to each other and other networks.

Not only do these advantages apply to LAN-to-LAN and LAN-to-host connections, but they also extend to telecommuters and remote LAN access. From a home or branch office, employees can log-in to the company server and work as if they never left corporate headquarters. Workers in different divisions, offices, campuses, and locations are still capable of collaborating on the same product. Numerous employees could access the same data bases, programs, and files via high-speed ISDN lines.

While advances in the remote information market has further deepened the physical separation between employees, communication technology has tried to maintain feelings of a corporate community through electronic mail (e-mail) and video conferencing. Although analog lines have sufficient bandwidth to support electronic mail with no attachments, affordable video conferencing is only possible with ISDN. Digital lines have the capacity to deliver simultaneous two-way voice, video, and data connections. Therefore, video conferencing allows people to set up virtual meetings as if the were talking face-to-face.

Communicating over the Internet is the most efficient way to promote a corporate presence around the world. Since information is always accessible, time zones become meaningless. The World Wide Web gives customers 24 hour access to a company's web site. From this site, potential clients have access to company literature, updates on current events and special pricing, and advertisements for new product releases. The company can e-mail brochures and ftp files without paying for traditional circulation and reproduction charges. Corporations can extend their web site's features by incorporating commerce applications. ISDN provides rapid and reliable credit card verifications and order entries. Buying merchandise on-line becomes as simple as going to the corner market.

ISDN at Home

Although most of the ISDN applications were developed for corporations, they still apply to consumers. These individuals want to improve their information, data, and communication capabilities. The Internet serves individuals in their day-to-day personal lives. Users can e-mail their friends, search for employment listings on the World Wide Web, and access interactive gaming networks. Higher data rates and faster connection times from ISDN helps telecommuters work more efficiently and productively from home. They access the corporate server to download files, access databases, and check their e-mail. For home businesses, ISDN lines improves Internet access. With a web site and e-mail account they can communicate with clients, access remote information, market products on-line, and engage in electronic commerce. An Internet presence puts home businesses in the same game with larger corporations, but an ISDN line makes it a competition.

Do you want to learn more about ISDN? Gain access to the abundant resources available on the World Wide Web through the ARESCOM ISDN Resources page.