ISDN - Take Another Look Copyright 1990 CAUSE From _CAUSE/EFFECT_ Volume 13, Number 2, Summer 1990. Permission to copy or disseminate all or part of this material is granted provided that the copies are not made or distributed for commercial advantage, the CAUSE copyright and its dateappear, and notice is given that copying is by permission of CAUSE, the association for managing and using information resources in higher education. To disseminate otherwise, or to republish, requires written permission. For further information, contact CAUSE, 4840 Pearl East Circle, Suite 302E, Boulder, CO 80301, 303-449-4430, e-mail info@CAUSE.colorado.edu IDSN -- TAKE ANOTHER LOOK by Gene T. Sherron ************************************************************************ Gene T. Sherron is Associate Vice President for Computer and Information Resources and Associate Professor of Information and Management Sciences at Florida State University. In his administrative position, he is responsible for coordinating academic and administrative computing. ************************************************************************ ABSTRACT: Few information technology managers can keep up with the significance of more than a handful of the technologies that saturate the trade publications, especially when the focus is on the technology rather than its implications. Has there ever been a more misunderstood topic than ISDN? This article provides a quick overview of ISDN for the IT manager on campus. Why do campus information technology managers know so little about ISDN? From my perspective, there are at least two reasons: (1) the first articles we read about it were written by telecommunications experts whose concession to a short, comprehensible explanation of ISDN was spelling out the acronym (Integrated Services Digital Network); and (2) vendors happen to sell a product that has been made possible by adoption of an ISDN "standard," and that product unfortunately has become our image of the scope of ISDN when, in fact, it is only one manifestation of it. There is increasing recognition of the urgent need for teamwork among vendors, suppliers, consultants, and users in addressing the challenges posed by ISDN, especially for a common understanding of ISDN and an open door policy so the discussion is not all smoke and mirrors.[1] For some of us in higher education, there may be a third reason for lack of understanding of ISDN, i.e., that our data communications requirements are so well met through our campus backbone networks and their connections to national and international networks that we have not felt the need to learn more about ISDN. However, the potential of a universal digital network that provides integrated voice and data services does have some implications for campus communications, particularly with the public sector. These implications are outlined below, but before discussing the significance of ISDN, let's define what it is. What is ISDN? ISDN is not a single piece of equipment, nor is it an application. Put simply, ISDN is a modest set of broad technical recommendations promulgated by an international standards committee (the International Telegraph and Telephone Consultative Committee, commonly referred to by the acronym CCITT) for a common user interface to digital networks all over the world. The first definition of ISDN, published in 1984, described a system that would provide simultaneous voice and high-speed data transmission through a single channel. It is this standard that has caused all of the excitement and discussion about ISDN over the past five years. The ISDN vision to provide a new approach to long-distance communication can be outlined in four concepts: (1) ISDN provides an internationally accepted set of standards for voice, data, and signaling; (2) significantly more bandwidth will be made available at the desk; (3) all transmission circuits will be digital, from one end to the other; and (4) the overhead types of signaling will be standardized and on a separate, more efficient data channel (out-of-band)[2] The first two words of ISDN -- integrated services -- help define how the first two goals of the ISDN concept will be applied: to combine all communication services currently offered over separate networks into a single network to which any subscriber has access over common facilities through a single plug in the wall. With the basic ISDN offering, on a single pair of wires you get three channels. Two are bearer ("B") digital channels of 64 kilobits per second that can be used for all types of transmission from voice to slow-scan television. The other channel (referred to as the "D," for digital, channel), of 16 kilobits per second, is used to control how the two bearer channels are used. This is called "2B+D" service.[3] The ISDN standards include higher bandwidth channels of varying speeds, from 384 kilobits per second through 45 megabits per second. These standards are in various stages of development for the future. Why is ISDN significant? Since its early days, ISDN has been called a technology in search of an application. But as everybody knows, the trumpeted arrival of new technologies means little or nothing until customers see real, immediate, and profitable benefits in their development. What's wrong with America's current phone system? The "indictment" reads like this: * It has been an analog system for a hundred years and everything is becoming digital. * Its copper, twisted-pair, narrow-bandwidth wiring is expensive and inefficient, and the trend is now fiber optic. * Data networks are growing in importance, yet they are being developed independently of voice and are even administered separately. * Standards abound, even international standards for voice, data, and digital interface, but will they all match up in the end? In the past two decades, telephone companies have gradually been transforming their network from analog to digital facilities. Yet voice and data networks have been developed separately. Digital facilities on the phone network are primarily available within and between major cities, while voice services are available internationally. We live in a dynamic world that requires widespread, including international, voice and data communications of equal quality. There is growing need to integrate communications and computing, with increasing use of PCs in networks, the proliferation of local area networks, and the growing importance of distributed computing. At the same time that the international standards are developing in ISDN, there is evidence of an almost worldwide need to modernize switching and transmission equipment, to extend the availability of public networks, and to take full advantage of technological progress, particularly in digital, satellite, and fiber-optic techniques. The integration suggested by ISDN is the only technology on the immediate horizon that promises ubiquity in binding the various communications and computing technologies into a coherent whole, allowing integrative solutions across all sectors -- government, education, and business. ISDN will allow the telephone companies to complete the transformation of their network to digital facilities and to standardize that process. Digitization provides two categories of benefits. In the first category are voice communications enhancements, service center improvements, and better security and privacy features. The second category relates to accommodating to other non-voice message services such as videotext, teleconferencing, and data exchange. It is this second category that has the most relevance for higher education. ISDN should give us new instructional applications from its integrated voice, data, and video capabilities. In turn, this could lead to an enhancement of our public service functions and other campus service center capabilities to better serve students. At first glance, ISDN may seem unnecessary to colleges and universities that are already connected to medium-speed networks such as the Internet and are planning connections to high-speed networks such as the proposed National Research and Education Network (NREN). Larger institutions will use these networks for the largest part of their communications with other institutions. However, ISDN could be a valuable supplement for the following applications: * Business communications with private industry (for example, ISDN could be used to send orders to suppliers of goods and services to the campus, using electronic data interchange standards). * Communications with the international educational and research communities that the educational networks do not reach. * Communications to corners of a campus that the backbone network does not reach, or to properties separated from a main campus. * Communications to faculty and student homes. Where is ISDN today? Judging by the rate of acceptance in the industry, ISDN services will likely interconnect most major cities by 1995, and by the year 2010, complete domestic coverage and international connections will become possible.[4] It is estimated that we began 1990 with over 250 central offices with ISDN hardware and software capabilities. The industry boasts that these local exchanges have the capability to serve half a million customers, but at the end of last year, it was estimated that there were only about 130,000 ISDN basic rate lines in use[5] Based on a survey of a dozen of the major local exchange companies, there are only about 160 ISDN subscribers in the United States. Many of the early users and biggest fans are companies developing ISDN products.[6] Not to be left out, all of the major interexchange carriers (long-distance telephone companies) have some ISDN services today and are moving toward making these services available throughout the U.S. To summarize where we are at present: ISDN is available only in limited areas; ISDN equipment is expensive; interesting or innovative applications are few; pricing remains uncertain due to a lack of tariff filings; and interconnection between LATAs is very limited (LATA is the acronym for Local Access and Transport Area or the area within which a local telephone company offers service). These problems have not stopped some from enjoying the benefits of ISDN today. Among the benefits cited by subscribers are reduced communications costs; greater flexibility in allocating bandwidth; easier wiring schemes; cleaner transmission lines; and improved employee productivity[7] What about calling-party ID? Integral to ISDN's ability to produce new customer services is the CCITT standard referred to as Signal System Number 7, approved in 1984. This particular standard, which sets up a channel for the exchange of control and management information among switching centers, allows two things. First, it removes all phone calling from the present telephone network onto a separate packet-switched data network. Thus it will provide enormous economies of bandwidth use. Second, it broadens the information that is generated by a call, or call attempt. Such transaction capabilities deal with remote database interactions or take advantage of the intelligence of today's digital central office switches in talking to each other from remote distances. Information they will exchange, like the phone number of the person who is calling (referred to as "calling party ID"), will significantly broaden the number of useful new services the ISDN telephone network of tomorrow will be able to offer.[8] And as I write, there is a controversy brewing about invasion of privacy when the caller's telephone number is disclosed even before the phone is answered on the other end.[9] What else can we expect? Recent announcements by DEC (Computer Integrated Telephony) and IBM (CallPath) indicate that ISDN technologies and call control capabilities will be used by major computer vendors and integrated into mainframes via a PBX or the central office switch. Such computer-based systems provide coordinated voice and data transfer of the terminal screens and voice calls. A host computer matches incoming call information with a customer database and hands it off to the appropriate agent. The personal computer will likely become the ISDN desktop device due to its large installed base and broad range of uses. Once communications applications software is available, the PC connections to ISDN's basic rate interface will increase dramatically. As mentioned earlier, there are hundreds of central office switches capable of ISDN, hundreds of thousands of ISDN lines ready and waiting, and a broad range of digital phones, adapters, PBXs and other products awaiting user demands. Thus, we can expect the next surge of ISDN advancements to be in software (applications) rather than hardware.[10] Along these lines, Apple Computer, Inc. recently announced its plans to begin to seed to hardware and software developers a limited number of ISDN Developer Toolkits, which will allow them to create ISDN applications on the Macintosh. To prepare your campus for ISDN, you might begin with the examination of long-range goals for use of networking to benefit your major operations, including business functions. ISDN compatibility should be considered in the acquisition of all major telecommunications system components, including cabling system design. Even if you are entertaining a bid for Centrex service from your local phone company, you should request ISDN compatibility. Access to the full capabilities allowed by ISDN will require the acquisition of certain special equipment on the campus. It must link to your central office equipment and the other regulated carriers, all of which are rapidly installing ISDN-compatible equipment. From a technical standpoint, ISDN is undoubtedly attractive and on the horizon. Yet it cannot be an end in itself -- only a means to satisfy users' present and future needs[11] ======================================================================== Footnotes 1 Peter Meade, "Reporting from the ISDN Front," Communications Consultant, July 1989, p. 4. 2 Harry Newton, ed., The Teleconnect Dictionary (Chelsea, Mich: Bookcrafters, 1987), p. 218. 3 "ISDN -- What Is It and Do I Really Need It?," The Office, July 1987, p. 84. 4 David M. Rappaport and Cory Van Wolvelaere, "ISDN: Two Key Points to Remember," The Office, September 1986, p. 88. 5 William C. Kanupke, "The ISDN Report," Communications Consultant, July 1989, pp. 18-20. 6 Dawn Bushaus and Paul Travis, "Users Find ISDN Pays Off," Telephony's ISDN Special (Supplement to Telephony), February 1990, pp. 12-15. 7 Paul Travis, "ISDN -- The Promise and the Reality," Telephony, 5 February 1990, p. 6. 8 Ron Bravo, "A Vendor's View of Stepping Stones," Communications Consultant, July 1989, pp. 22-23. 9 Charles Mason, "Congress Gets Caller ID Bill," Telephony, 5 February 1990, p. 9. 10 Ann Lindstrom, "Big and Small Vendors Form ISDN Hunting Party," Telephony's ISDN Special (Supplement to Telephony), February 1990, pp. 28-29. 11 Lee Alley and Stephen D. Willits, "ISDN -- What It Means to Information Technology Administrators on Campus," CAUSE/EFFECT, Fall 1988, p. 10. ========================================================================