Computer Networks (1976)最新文献

Major requirements of a future telecommunications network called INS are outlined and key technologies needed to help meet these requirements described. INS is envisioned as requiring construction of a transmission and switching system, communication and information processing equipment, equipment for use on customer premises and the application of network management and control system technologies supported by such fundamental technologies as LSI and fiber optics. INS technology must include means for composing a telecommunications network and its subsystems, network architecture and network structure.

This new telecommunications network will make it possible to respond to the diverse requirements for voice and non-voice services through overall utilization of digital technology and enhanced network capabilities.

An Information Network System (INS) as the basis of a new world information order. Maximum advantage is to be made of the marriage between telecommunications and computer technologies in implementing the information network. A bit rate tariff system is also proposed to make INS feasible on both a national and international scale. As the community of man transforms itself, on the shoulders of INS, into an advanced information society, the human and technical weaknesses inherent in such a society must be addressed. By harmonizing the natural and social sciences with the needs of humanity, the technological and information-oriented innovations accompanying INS are expected to greatly enrich the quality of life.

The construction of a pilot for “Information Network System” (INS), started recently, is a milestone in INS development. The pilot plant, called a Model System, started its five-year field trial in September, 1982. Through the test, studies will be made on technical feasibility and service requirements. Further, an intensive assessment for the formation of INS will be made from the viewpoints of the social and cultural sciences. With the results obtained from the Model System, comprehension of what INS can be gained, and problems relating to establishment of INS can be solved.

Local networks often consist of a cable snaking through a building with sockets in each room into which users can plug their personal computers. Using such a network for building a coherent distributed or network operating system is difficult because the system administrators have no control over the user's machine — not the applications programs, not the system kernel, not even the choice of hardware. In this paper we discuss a general method to protect such systems against malicious users without placing any restrictions on the kinds of operating systems that can be constructed. Depending on the details of the hardware, either one-way functions or public key cryptography forms the basis for the protection. As an example of our method, we show how a traditional object-oriented capability system can be implemented on top of the basic protection mechanism, and how a service for accounting and resource control can be constructed.

A multidestination protocol is a data transfer procedure from one transmitter to many rceivers. We specify and verify such a protocol, the Selective Repeat procedure. The communication medium assumed is a satellite broadcast channel shared by using a time division multiplexed technique.

The Selective Repeat procedure is modeled as a parallel program in a Pascal-like language. Then, we show the correctness of the parallel program model using temporal logic. The correctness requires that the program model have two system properties: the safety and liveness properties. The safety property ensures that each receiver delivers the packets to the user in the same sequence as originally delivered to the transmitter. The liveness property ensures that each receiver delivers an infinite number of packets to the user if an infinite number of packets are waiting to be transmitted at the transmitter.

This paper describes how the error detection and recovery mechanisms of the proposed National Bureau of Standards (NBS) transport layer protocol can be easily extended to provide secure transmission of information. The security mechanisms are based on the Data Encryption Standard (DES) of the NBS. Two distinct security architectures are described. In the first, the DES hardware is a peripheral I/O device of the computer in which the transport layer resides. In the other, encryption is performed by a hardware device located in the data path between the transport layer and the network layer. The paper argues that, in the long run, the transport layer should be implemented in a front end computer equipped with a DES peripheral. This isolates it from (possibly untrustworthy) host software, and greatly simplifies the job of certifying its correct behavior.