Toward the Private ISDN; A View of Corporate Voice-Data Networks.
The rapid and, at times, traumatic evolution of the information communications industry which is occurring today, and which will continue throughout the remainder of the decade, will have a profound impact upon the future of corporate communications. In just a few years, the combined effects of restructuring within the telecommunications industry and emerging technological capabilities will result in new patterns of integrated business communications with increased requirements for functionality and flexibility for the user. This comes about partially because of the higher levels of networking, both voice and data, which corporate users are employing in their communications applications and partially because of the attractive economics of all digital transmission and processing.
For some years, the concept of an Integrated Services Digital Network (ISDN) has been the target toward which public communications networks both international and domestic have been migrating. While more formal definitions of the underlying architecture and standards for ISDN have only recently been discussed, early building blocks including digital transport and switching capabilities have been within the public domain for some time. However, many elements of the true ISDN remain undeveloped and actual deployment is still in the future.
From a purely functional (as opposed to implementation) standpoint, the concept of an ISDN bears great relationship to what can be done in integrated digital networks which will be implenented by private corporate users in the near future. To the extent that such networks share characteristics with planned public networks they could, in fact, be termed ISDNs in a generic sense. Furthermore, as standards for ISDN network interfaces are better defined, the private network will evolve toward an even closer degree of compatibility. One example of this is application of X.25 and related protocols defined for packetized data applications. Many vendors already provide such interfaces. Another direction, is the combination of 64 kb/s "clear' channel transmission utilizing separate signaling channels for high-capacity, all-digital interfaces. Not only do such interfaces afford higher channel throughput, but could provide extended feature capability via separate channel signaling. In fact, future developments in all-digital PBX-based networks will allow high levels of functional transparency between customer premises and greater network flexibility through node to node signaling. Once standard digital signaling interfaces are available to the public network, the intelligence in the customer premises switch could possibly allow communications with the network to provide better call recording, interaction with public network features, allow utilization of specialized routing or call handling capabilities within the public network, and other new ways of increasing functionality for the end user.
The private integrated voice/data digital network is in some areas out front of public ISDN implementations for reasons aside from standards questions, architecture, and technology. Most important here is the local distribution issue. While the ubiquitous all-digital loop plant for public applications is still somewhat in the future, for the private corporate user, high function digital connectivity to the digital PBX or LAN is current technology. This includes use of optical fiber distribution to the end user workstation. Through the use of universal jacks, the end user can access voice, switched data, or packetized data networks directly in an integrated digital format.
As public networks begin to evolve capabilities and features mirroring the concept of ISDN, private networks will also evolve to take advantage of these capabilities to provide lower cost and more functionality for the user.
Standard signaling interface and message set definitions for common channel signaling between customer premises based network nodes and public network will expand the features available to private network customers. In such a scenario communications between intelligent switches on the customer premises and Signaling Transfer Points (STPs) equipped with processing capabilities could allow better call accounting and recording as well as facilitate synergistic use of new public network features.
Several Interexchange Common Carriers have announced plans for intelligent routing and call manipulation capabilities within the public network. Generically called Software Defined Networks, these are extended services offerings tied to intelligence in the public network. In many cases, features available to the private network user could be mirrored using public-switched facilities. Private networks will evolve to include such capabilities in order to obtain wider feature coverage to small locations or those which do not support intelligent PBXs. Looking further into the future, with common channel signaling interfaces in an all-digital environment, feature capabilities will likely be distributed between private and public networks. In such situations, specific routing or number translations, data manipulation and switching (including high speed and packet switching) and call recording and accounting could functionally occur anywhere within the network between end users or processing applications with little distinction between public or private vehicles.
As the potential for features within the public network could expand through implementation of ISDN, other examples of the relationship between public and private networks will become clearer. What is obvious is that standardized digital interfaces and distributed network processing associated with ISDN will encourage close interaction between the two.
Integrated voice/data digital networks for private business applications represent a technology which is here today. Functionally, they closely relate to ISDN public networks of the future despite potential architectural and implementation differences. Interest in such networks is the result of economics available through use of digital transport and the functional capabilities which end users can achieve. In the future, ISDN capabilities in public networks will be mirrored in private business networks and functional synergies will be achieved through interaction between the two. In the near term, however, private integrated voice/ data networks represent a viable first step toward ISDN, one which an increasing number of corporations will embrace with much enthusiasm.
|Printer friendly Cite/link Email Feedback|
|Date:||Jan 1, 1985|
|Previous Article:||Communications Managers in Pivotal Role As Function Gains Increased Visibility.|
|Next Article:||Office Modernization Requires a Functional-Integration Approach.|