Multi-rate ISDN

Multi-rate integrated services digital network (ISDN) is a new technology for providing dialed-up, circuit-switched, isochronous communications for bandwidths from 128 kb/s to 1.536 Mb/s (DS-1) or 1.920 Mb/s (CEPT-1). Multi-rate ISDN provides a simple way to extend ISDN network services to match the higher bandwidth requirements emerging for videoconferencing, multimedia, imaging, and other high-speed applications. Using this technology, network service providers can offer high-speed connectivity within the boundaries and benefits of existing, circuit-switched, central office and transmission equipment. Only minor changes are required in the operations administration and maintenance and provisioning (OAM&P) procedures associated with multi-rate ISDN, versus existing ISDN transmission and central office maintenance procedures     

Common channel signaling for international service applications

The message transfer, telephone user, and integrated services digital network (ISDN) user parts of CCITT Signaling System No.7 (SS7) are described. The introduction of SS7 to provide control of international circuits is described. The intent is to provide a perspective on the advantages of using common channel signaling for ISDN     

Current role and future evolution of the ISDN Signaling system inNTT's network

The current role of the integrated services digital network (ISDN) Signaling System is examined, covering general features of the ISDN protocol, functionalities supporting ISDN services, and functionalities supporting existing services. The Signaling System No.7 (SS7) network and its operation are described. The future evolution of the ISDN signaling system is discussed     

Personalizing ISDN

It is argued that making integrated services digital networks (ISDNs) more popular among personal computer users is essential for ISDN to prosper. Users in offices, businesses, and at home form a large potential ISDN market. Existing ISDN interface modules such as ISDN adapter boards for personal computers, are limited to ISDN features and can hardly handle the various needs of personal users. An ISDN interface module for personal computers must be designed to handle various applications and provide any-to-any communications. An ISDN personal computer interface developed to handle digital and analog communication protocols and flexibly combine resources is described     

ISDN applications at Tenneco Gas

The evolution from analog to integrated services digital network (ISDN) telecommunication services at Tenneco Gas and the features of its telephone system are described. The results of implementing ISDN in data operations are examined. The benefits of ISDN for Tenneco are briefly summarized     

ISDN Terminals and Integrated Services Delivery

This paper proposes that the end user's perception of an "ISDN service" should reflect'three interrelated ISDN aspects, namely:bulletISDN terminal capabilities,bulletISDN access capabilities, andbulletISDN network capabilities. Emphasis is placed on the ISDN terminal capabilities in supporting integrated services delivery of different levels to the end user (e.g., integrated bearer services and integrated teleservices delivery). Such a concept, integrated services delivery, is seen to suggest a useful framework for developing a wide range of possible ISDN commercial service/ product offerings. An ISDN service scenario is also described to illustrate some important communication capabilities made possible by an ISDN environment.     

The role of ISDN in data networking

The integrated services digital network (ISDN) offers on-demand switched end-to-end digital connectivity over the wide area, enabling the integration of both voice and data services over a common core network. This paper considers the role of ISDN in data networking, both as the core transport network and as a means of enhancing resilience in a mixed-technology data solution, complementing other data network technologies. The issues associated with data transport based on an ISDN solution are considered, and include security, bandwidth utilisation, scalability and the management of ISDN-attached devices. Optimising the use of ISDN networks for supporting the most prevalent routed and routeing protocols is also discussed.     

ISDN Activities in Italy

Digitalization of the Italian telecommunications network is underway, as in many other countries, and a significant diffusion of digital transmission has already been achieved. Digital switching has already been introduced at both transit and local levels, with some 450 exchanges presently in operation. Both packet- and circuit-switched data networks are in operation. CCITT No. 7 is presently being introduced. In this network scenario, the already planned Italian developments towards the ISDN will include the provision in 1986 of 64 kbit/s digital connectivity and, two years later, the activation of a pilot ISDN service, whose main characteristics are described in the paper. An overview on further developments in ISDN research areas is also given.     

Services and supporting architecture of the ESA OBP system

The ESA on-board processing (OBP) satellite system using on-board regeneration and baseband circuit switching has been designed to provide ISDN connectivity and services to users on a Pan-European basis. It is thus seen at its periphery as a 2 Mb/s primary rate access, hence allowing for the interconnection of equipment and terminals compatible with this standard interface. Among the various possible network architectures that the system could support, the business-oriented closed networks look most promising. It has therefore been retained as a prime design driver for OBP system developments. Optionally, connectivity can be offered in an optimized manner to pure data networks, e.g. for LAN-to-LAN interconnection at rates up to 1 Mb/s. In the paper, communication services and networking capabilities offered by the system are briefly reviewed. The internal characteristics of the satellite system allowing for such capabilities are then reviewed and the corresponding performance outlined. The system is shown to be compatible with critical CCITT performance criteria.     

Implementation in Japan [ISDN]

INS-Net, Nippon Telegraph and Telephone's (NTT's) commercial integrated services digital network (ISDN) service, is described. There are two types of INS-Net service. INS-Net 64 provides basic rate interface service, and INS-Net 1500 provides primary rate interface service. The implementation of INS-Net and the promotion, application, and penetration of ISDN services are discussed. It is argued that as the number of useful applications grows, the number of subscribers will rise accordingly, particularly among business users. This increased volume of both applications and users will in turn lead to lower ISDN CPE costs, and will make ISDN an indispensable means to business activities in the 1990s     

Reliability and evolvability: requirements for the design of ISDNcommunication software

The ISDN (integrated services digital network) is characterized by the breadth of services to be supplied and the complexity of the protocols involved. Moreover, the ISDN services evolvability is an essential requirement which must be taken into account by telecommunication systems schedule. An approach to improving the quality of telecommunication products is described that is based on a formalization of communication functions. The compilation of the specifications provides a means of validation and allows the generation of an implementation and of qualification tests. This process is illustrated by an example of its use on an Alcatel E10 system component     

ISDN protocols for connection control

The technical details of the integrated services digital network (ISDN) access protocols for connection control are described. These protocols are the ISDN physical layer, link layer, and layer 3, which are documented in International Telegraph and Telephone Consultative Committee (CCITT) Recommendations I.430, I.441, and I.451, respectively. Other work that supports or enhances these protocols is described. In particular, the ISDN protocol reference model, how it relates to the open systems interconnection reference model, and CCITT Recommendation Q.932 on service feature control on ISDN are discussed. Possible uses of ISDN, possible evolution paths, and some understanding issues related to ISDN are also described     

Why are ISDN standards important?

The advantages offered by the integrated services digital network (ISDN) to US Department of Defense (DoD) communications in terms of interoperability provides a framework for a discussion of ISDN standards. The standards organizations working on ISDN and network protocol standards are described, and their relationship to each other is delineated. The status of the standards being developed is discussed, and those that would be of special interest to the US DoD are examined     

ISDN implementation strategy of the Deutsche Bundespost telekom

The telephone networks operated by the Deutsche Bundespost are described, and its 64-kb/s ISDN pilot project is introduced. Plans for commercial operation are discussed. Marketing principles surrounding the introduction of ISDN services are examined. Conditions of use and charges in ISDN are considered, focusing on the effects on tariffs caused by the transition to ISDN, and the effects of the proposed switch from periodic pulse metering to time-sensitive calculation of charges are discussed     

VSAT-enhanced ISDN: architectures and implementation

The authors discuss the applications of very small aperture terminals (VSATs) to the ISDN. Typical VSAT network architectures include point-to-point interactive, point-to-multipoint broadcast, and interactive star configurations. VSATs and satellite communications have found new applications for integrated network solutions yielding hybrid network architectures that mix terrestrial and satellite segments. These issues and their implications are examined in the context of ISDN. Six hybrid network configurations are described to address various applications. A proof of concept implementation utilizing a hybrid terrestrial/satellite ISDN network was performed. The demonstration showed the feasibility of using hybrid networks as a backup for terrestrial communications as well as for service extension via satellite. The architecture and implementation of this configuration are described     

Interworking IEEE 802/FDDI LANs via the ISDN frame relay bearerservice

The author presents a generic architecture for interconnecting LANs (local area networks) through the ISDN (integrated services digital network) bearer services, particularly the frame relay bearer service. The architecture is derived from the IEEE 802.1 MAC (medium access control) bridge and ISDN frame relay standards. An algorithm for MAC/ISDN address resolution that makes minimal use of the WAN (wide area network) bandwidth (which is potentially the most expensive resource) is presented. The algorithm uses a MAC/ISDN address resolution server to resolve addresses for new stations, the resolution in all other cases (e.g. stations moving from the ISDN address to another) being fully distributed. To prevent a server failure from inhibiting communication to new stations, a backup server may be provided. A practical implementation of the architecture has been found capable of supporting full throughput at ISDN hyperchannel rates (384-1920 kb/s) for all IEEE 802.3 frame lengths. Frame relay is seen as having a number of important advantages for LAN interconnection, including the following: a large number of virtual circuits available, giving the potential for a rich interconnection architecture with single-hop connections across the ISDN; and low processing overhead enabling efficient use of ISDN channels, including ISDN hyperchannels (384-1920 kb/s)     

Object-oriented design of ISDN call-processing software

The development of object-oriented programming (OOP) software for a prototype switching system, including the DSS1 protocol on integrated services digital network (ISDN) subscriber signaling and the ISDN user part (ISUP) for network signaling, is discussed. The major goal of the project is to determine whether switching system software can be clearly structured by using the rules of OOP, and whether the use of OOP concepts leads to an improvement in productivity and quality for large software systems. The standard classes, application classes, class hierarchy, and layer model with the OOP project are described. The experiences in applying OOP for the development of switching system software are summarized     

Working at home [ISDN role]

The benefits of working at home, supported by the integrated services digital network's (ISDN) high-capacity bandwidth and public network ubiquity, are discussed. The business case for telecommuting is presented. The roles of ISDN and the communications industry in promoting telecommuting are described     

A 64 kbit/s Integrated Visual Communication System--New Communication Medium for the ISDN

Seeing-while-talking has been a dream of mankind for over a 100 years since the invention of telephone. In the past, various trials were performed in spite of the difficulty in installing the network for the actual service. However, with the progress of ISDN and the advancement of digital signal processing technology, the environment has been changing rapidly. In this paper, an integrated visual communication system is described for the enhanced communication service at 64 kbits/s, the fundamental bit rate of ISDN. The roles of state-of-theart compression of the audio and video signals are discussed and an integrated transmission method based on the priority of the information content is proposed.     

Integrating ISDN and OSI: an example

A successful multivendor trial demonstrating the integration of Open Systems Interconnection (OSI) and integrated services digital network (ISDN) technologies is discussed. The planning, staging, and results of this trial, which demonstrated ISDN as a viable transport technology for OSI data applications, are detailed. The technical requirements to be fulfilled and the initial plans are outlined. The actual configuration used is described, and the results are summarized