bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstraction mechanisms in CLU
Authors: Liskov Barbara , Snyder Alan , Atkinson Russell , Schaffert Craig 
Published: October 2004

CLU is a new programming language designed to support the use of abstractions in program construction. Work in programming methodology has led to the realization that three kinds of abstractions, procedural, control, and especially data abstractions, are useful in the programming process. Of these, only the procedural abstraction is supported well by conventional languages, through the procedure or subroutine. CLU provides, in addition to procedures, novel linguistic mechanisms that support the use of data and control abstractions.
This paper provides an introduction to the abstraction mechanisms in CLU. By means of programming examples, we illustrate the utility of the three kinds of abstractions in program construction and show how CLU programs may be written to use and implement abstractions. We also discuss the CLU library, which permits incremental program development with complete type-checking performed at compile-time.
Development of the domain name system
Authors: Mockapetris P. , Dunlap K. J. 
Published: October 2004

The Domain Name System (DNS) provides name service for the DARPA Internet. It is one of the largest name services in operation today, serves a highly diverse community of hosts, users, and networks, and uses a unique combination of hierarchies, caching, and datagram access.
This paper examines the ideas behind the initial design of the DNS in 1983, discusses the evolution of these ideas into the current implementations and usages, notes conspicuous surprises, successes and shortcomings, and attempts to predict its future evolution.
A mesh/token ring hybrid-architecture LAN
Authors: Kang C. , Herzog J. 
Published: October 2004

This paper presents a hybrid architecture for local area networks (LANs) which combines the advantages of token ring and mesh networks while remaining relatively simple. Each node may have two communication channels. The first is a token ring and is used for short or prioritized message data transmissions. The other consists of an arbitrary collection of data links, which are used for relatively high volume and low priority data messages. With this architecture, a LAN can be installed in the form of token ring and can be upgraded and “tuned” to its application environment by the insertion of node-to-node data links.
Simulation results indicate that even with rather simple network control and routing algorithms, performance is improved over token ring due to data transmission concurrency greater than one.
The VMP network adapter board (NAB): high-performance network communication for multiprocessors
Authors: Kanakia H. , Cheriton D. 
Published: October 2004

High performance computer communication between multiprocessor nodes requires significant improvements over conventional host-to-network adapters. Current host-to-network adapter interfaces impose excessive processing, system bus and interrupt overhead on a multiprocessor host. Current network adapters are either limited in function, wasting key host resources such as the system bus and the processors, or else intelligent but too slow, because of complex transport protocols and because of an inadequate internal memory architecture. Conventional transport protocols are too complex for hardware implementation and too slow without it.
In this paper, we describe the design of a network adapter board for the VMP multiprocessor machine that addresses these issues. The adapter uses a host interface that is designed for minimal latency, minimal interrupt processing overhead and minimal system bus and memory access overhead. The network adapter itself has a novel internal memory and processing architecture that implements some of the key performance-critical transport layer functions in hardware. This design is integrated with VMTP, a new transport protocol specifically designed for efficient implementation on an intelligent high-performance network adapter. Although targeted for the VMP system, the design is applicable to other multiprocessors as well as uni-processors.
Circuit switching in multi-hop lightwave networks
Authors: Chlamtac I. , Ganz A. , Karmi G. 
Published: October 2004

Emerging high speed networks are using optical fibers employing time division synchronous communication. In these systems the use of optical switching is strongly advocated due to the bottleneck created by store and forward in electronic components. Switching solutions geared toward optical systems have been proposed so far only for packet switching networks.
This paper introduces a new circuit switching approach for the emerging time division controlled fiber optic networks based on the requirement to avoid store and forward at intermediate nodes. The approach, termed Fast Circuit Switching (FCS), is unique in several operational and performance aspects. In terms of the way time slots within each cycle are allocated, a circuit is guaranteed a transmission slot immediately upon arrival at every intermediate node. As a result, the proposed Fast Circuit Switching (FCS) can be implemented by pure optical switches. In terms of performance, FCS guarantees minimum data transmission delays, consisting only of the end to end propagation delay in the network. Lastly due to being based on fixed time allocation at intermediate nodes, the FCS controlled system is purely end to end controlled. These properties make FCS inherently suitable for efficiently implementing circuit switching in wide area fiber optic networks, particularly, for supporting real time communications.
The realization of slot assignments, which support the FCS solution, entails a novel graph oriented algorithmic approach. Several new algorithms for allocating circuits according to FCS are presented, dealing with fixed, as well as dynamic, circuit management. It is shown that, while providing unique operational and performance advantages as discussed above, the FCS is also bandwidth efficient, requiring only system bandwidth similar to conventional circuit switching methodologies.
Specification and verification of collusion-free broadcast networks
Authors: Jain P. , Lam S. S. 
Published: October 2004

For high-speed local area networks that offer integrated services for data, voice, and image traffic, a class of demand-assigned multiple-access protocols have been presented in the literature. These protocols exploit the directionality of signal propagation and enforce time constraints to achieve collision-freedom. A correct implementation of such a protocol requires a careful analysis of time-dependent interactions of event occurrences using a formal method. To date, most protocol verification methods are intended for the analysis of asynchronous communication over point-to-point channels.
We present a model for broadcast bus networks. The novel features of our model include the ability to specify broadcast channels and the specification of real-time behavior. The broadcast characteristics of cables or buses are captured by some simple axioms. Real time is modeled as a discrete quantity using clocks and time variables. Real-time properties are specified by safety assertions. To illustrate our model and analysis method, we present a specification of the Expressnet protocol. We found that to achieve collision-freedom, a small modification to the original Expressnet protocol is needed.
The Kiewit network: a large AppleTalk internetwork
Authors: Brown R. E. 
Published: October 2004

Dartmouth College's Kiewit Network connects nearly all of the computing resources on the campus: mainframes, minicomputers, personal computers, terminals, printers, and file servers. It is a large internetwork, based on the AppleTalk protocols. There are currently over 2900 AppleTalk outlets in 44 zones on campus. Over 90 minicomputers act as bridges between 177 AppleTalk twisted pair busses. This paper describes the extent and facilities of the current network; the extensions made to the AppleTalk protocols, including a stream protocol and an asynchronous link protocol; and current development projects, including an AppleTalk stream to TCP converter.
The Kiewit Network is a general purpose local data network. It serves as glue between all the host computers and nearly all the personal computers and terminals on campus. The network extends to the academic and administrative buildings, and the student residence halls, with network ports placed in almost all the offices and rooms. From these ports, users may access any of the host computers connected to the network. In addition, the hosts use network connections to communicate between themselves for electronic mail, file transfer, printer sharing, etc. The network also supports Apple Computer's AppleTalk® protocols. Departments and individuals can purchase standard devices which use AppleTalk (such as LaserWriters® and file servers), and connect them directly to the network.
The Kiewit Network is not part of the telephone, energy control, or security systems of the College. While there can be benefits from combining them, separating these systems has simplified our design in many ways. A network failure doesn't interrupt these other services. We can also schedule experimental time for testing new software at our convenience.
Dartmouth College started its campus network with General Electric Datanet 30 computers acting as front ends for the Dartmouth College Time Sharing (DCTS) system. In 1978, as the requirement for ports grew, Honeywell 716 minicomputers replaced the Datanet machines. In the same time period, two factors forced a change in perspective away from a front-end function toward a networked approach. New hosts began to arrive on campus. These new machines required enhancements to the network. Second, off-campus sites demanded more ports than the existing phone lines could supply. We served these remote users by using Prime P200 minicomputers as statistical multiplexors. In 1980, we implemented the DCTS terminal handling protocols on a less expensive minicomputer, and began to place these network nodes in the basements of buildings across the campus.
When the College recommended that the freshmen entering in the fall of 1984 purchase a Macintosh™ computer, funds were appropriated for three major network enhancements: installation of a network port for each undergraduate in the residence halls; conversion of the network to the AppleTalk protocols; and creation of a terminal emulation program to exploit the enhanced network capabilities.
Computer networking for large computers in Universities
Authors: Matsukata J. 
Published: October 2004

N-1 protocol was developed for construction of a computer network which connects universities in Japan. N-1 protocol has been adopted by Inter-University Computer Network and University Library Network.
NACSIS has started the construction of Science Information Network which will provide an infrastructure for digital communication for universities in Japan. High speed digital lines has been leased from NTT for that purpose.
A local area network was constructed at the Faculty of Engineering at the University of Tokyo. The network consists of an optical fiber backbone network and many IEEE802.3 10Mbps baseband networks connected to the backbone. Connection to large computers was one of the key issues in the planning of that network.
Algorithms for the reduction of timed finite state graphs
Authors: Masapati G. H. , White G. M. 
Published: October 2004

A set of algorithms to reduce the size of timed finite state graphs are presented. In particular, we develop a more general algorithm for vertex folding than those presently existing. It is based on the law of conservation of transition time. We demonstrate the application of these reduction algorithms to a version of the stop-and-wait protocol.
We have also developed a graph reduction software package incorporating all these algorithms which can be used in automated performance prediction. Graph reduction software tools such as these are important and form an integral part of automated protocol performance prediction tools[RUD 83].
Transparent interconnection of incompatible local area networks using bridges
Authors: Perlman R. , Varghese G. 
Published: October 2004

No single LAN technology is sufficient to interconnect all the computers in a given plant, campus, or site. Thus it is desirable to combine different types of LANs, using a device called a Bridge, to produce an Extended LAN. Some LANs in the Extended LAN may have incompatible Data Link formats. Thus a bridge may need to encapsulate a frame originating on LAN A inside the Data Link header of another (incompatible) LAN B in order to allow the type A frame to travel over LAN B. In general, frames sent between any pair of LANs in the Extended LAN must be encapsulated across every incompatible LAN in the path between the LANs.
Bridges learn their routing information from information contained in frames they forward. Besides the problems of distinguishing various kinds of encapsulated and unencapsulated frames, the encapsulating protocol used by bridges must also solve the learning problem. This leads to a new set of considerations and solutions. We begin with a rough solution, and refine it using informal arguments and examples to lead to the final description. The stages in the description roughly mimic the design process.
Recoverability of modular systems
Authors: Merlin Philip M. , Farber David J. 
Published: October 2004

In [1] GOSTELOW-VAN WEERT, it was shown that processes can be described by Petri-nets (PN). In this note we will demonstrate a way of designing programs using Petri-nets as a way of describing the desired behavior. This approach makes it possible to utilize all the theoretic knowledge developed for PN and thus provides a powerful tool for program design. In an example of this approach we show how to design a recoverable program. This design is based on a study of recoverable PN's presented in [2], [3], [4] and [5].
In this note, we will not deal with the code itself, but with the structural organization of the programs. Our approach is based on an hierarchical, top-bottom, modular design. At each level a description of the desired system behavior is given. This description is then modeled by a PN and analyzed using the theory developed for PN's.
This analysis allows one to check for, among other things, properties of the systems such as recoverability, proper termination, etc. These properties are inherently structural and not dependent on internal module semantics.
Performance
Authors: Chu Wesley 
Published: October 2004

Interprocess Communications play an important role in system performance in the throughput as well as in its reliability. McQuillan and Walden describe such design considerations as buffering and pipelining, error control, multiplexing and addressing, and flow control in interprocess communications. Danthine and Bremer proposed a model for representing protocols which can be used to verify the definition of the protocol and evaluate its system performance. Opderbeck presents measurement esults on performance of control procedures of the ARPA Network, which reveals that efficiency of the current protocol can be as low as 20% of line efficiency. While using a new host-to-host protocol an average of 30-40% efficiency can be achieved.
In order to reduce the overhead in interprocess communications, much thought must be given on the efficient implementation and use of protocols, rather than only on their feasibility. Much more work is needed to be done in this area.
Communication protocols in a network context
Authors: Danthine André A.S. , Bremer Joseph 
Published: October 2004

In a distributed computers network based on a packet-swltched communication subnet, it is possible to describe the system as a hierarchical structure. We will consider here only three levels:
-level 0: communication between nodes of the subnets.
-level 1: communication between hosts connected to the net.
-level 2: communication between users processes (subscribers) in different hosts.
At each level, the communication is based on a protocol and the data structures to be exchanged are different. For instance the data structure exchanged at level 2 may be a sequential file. As there is no direct support of communication at this level, it is through the mechanisms of level 1 and 0 that the transfer will take place with data structure at each level not directly related to the upper level one. The complete definition of the system will therefore required not only the level 0, 1 and 2 protocols, but also inter-level protocols.
In the following, we will concentrate on the level 1 protocol. It is the basic communication protocol of a network since it will be used by user processes in different hosts and it will use the subnet as a communication support. This level 1 entity is called a “TS” (transport station) in CYCLADES [13] and a “TCP” (transmission control program] in [2].
A methodology for protocol design and specification based on an extended state transition model
Authors: Chung Richard 
Published: October 2004

A lot of effort is being dedicated world-wide to defining Open Systems Interconnection (OSI) protocol standards and tools for formally describing them. However, little work is done in developing methods for applying these tools to the development of new protocols.
This paper presents such a methodology based on OSI and software engineering principles. It provides general guidelines for designing protocols based on an extended state transition formal description technique (FDT). It emphasizes a systematic, analytical and algorithmic approach to achieve completeness of protocol specification during the protocol design process. Its possible application to the development of OSI protocol standards is discussed and suggested for study by the standards community.
Protocol testing methdology development at NBS
Authors: Blanc Robert P. 
Published: October 2004

The National Bureau of Standards has three primary goals in computer networking.
1. To develop networking and protocol standards which meet U.S. Government and industry requirements and will be implemented in off-the-shelf, commercial products.
2. To develop testing methodologies to support the development and implementation of computer network protocols; and
3. To assist Government and industry users in the application of advanced networking technologies, and computer and communication manufacturers, in the implementation of standard protocols.
To support these objectives, NBS has laboratory activities where prototypes of draft protocol standards are implemented and tested in a variety of communications environments (e.g. global networks, local networks, office systems networks), supporting different applications (e.g. file transfer, message processing), on difference kinds and sizes of computers. The primary purposes are to advance the state of the art in measurement methodologies for advanced computer networking technologies, and to determine protocol implementation correctness and performance.
NBS views testing as a cooperative research effort and works with other agencies, private sector companies and other countries in the development of methodologies. At this time, this cooperation involves five network laboratories in other countries and over 20 computer manufacturers.
The test methodologies developed at NBS are well documented and the testing tools themselves are developed with an objective of portability and made available to many organizations engaged in protocol development and implementations.
Consistent with goals, NBS standards developments, research in testing methodologies, and technical assistance are characterized by direct industry/government cooperation and mutual support.
The implementation of a coherent memory abstraction on a NUMA multiprocessor: experiences with platinum
Authors: Cox A. , Fowler R. 
Published: October 2004

PLATINUM is an operating system kernel with a novel memory management system for
Non-Uniform Memory Access
(NUMA) multiprocessor architectures. This memory management system implements a
coherent memory
abstraction. Coherent memory is uniformly accessible from all processors in the system. When used by applications coded with appropriate programming styles it appears to be nearly as fast as local physical memory and it reduces memory contention. Coherent memory makes programming NUMA multiprocessors easier for the user while attaining a level of performance comparable with hand-tuned programs.

This paper describes the design and implementation of the PLATINUM memory management system, emphasizing the coherent memory. We measure the cost of basic operations implementing the coherent memory. We also measure the performance of a set of application programs running on PLATINUM. Finally, we comment on the interaction between architecture and the coherent memory system.
PLATINUM currently runs on the BBN Butterfly Plus Multiprocessor.
Performance of Firefly RPC
Authors: Schroeder M. , Burrows M. 
Published: October 2004

In this paper, we report on the performance of the remote procedure call implementation for the Firefly multiprocessor and analyze the implementation to account precisely for all measured latency. From the analysis and measurements, we estimate how much faster RPC could be if certain improvements were made.
The elapsed time for an inter-machine call to a remote procedure that accepts no arguments and produces no results is 2.66 milliseconds. The elapsed time for an RPC that has a single 1440-byte result (the maximum result that will fit in a single packet) is 6.35 milliseconds. Maximum inter-machine throughput of application program data using RPC is 4.65 megabits/second, achieved with 4 threads making parallel RPCs that return the maximum sized result that fits in a single RPC result packet. CPU utilization at maximum throughput is about 1.2 CPU seconds per second on the calling machine and a little less on the server.
These measurements are for RPCs from user space on one machine to user space on another, using the installed system and a 10 megabit/second Ethernet. The RPC packet exchange protocol is built on IP/UDP, and the times include calculating and verifying UDP checksums. The Fireflies used in the tests had 5 Micro VAX II processors and a DEQNA Ethernet controller.
New results on deriving protocol specifications from service specifications
Authors: Khendek F. , von Bochmann G. , Kant C. 
Published: October 2004

Previous papers describe an algorithm for deriving a specification of protocol entities from a given service specification. A service specification defines a particular ordering for the execution of service primitives at the different service access points using operators for sequential, parallel and alternative executions. The derived protocol entities ensure the correct ordering by exchanging appropriate synchronization messages, between one another through the underlying communication medium.
This paper presents several new results which represent important improvements to the above protocol derivation approach. First the language restriction to finite behaviors is removed by allowing for the definition of procedures which can be called recursively. Secondly, a new derivation algorithm has been developed which is much simpler than the previous one. Third, the resulting protocol specifications are much more optimized than those obtained previously.