waashk/acm huggingface dataset:
the iso reference model of open systems interconnection: a first tutorial  during the 1970's computing facilities which had previously provided stand- alone processing were linked into a variety of networks under quite different geographical, technical, financial and application constraints. the effect of these independent developments was that similar services were often provided by quite different mechanisms, and interconnection became extremely difficult.  late in the 1970's a strong desire for a standard means of internetwork communication arose. it was realized that a common model of distributed data communications would be required to facilitate the development of these standards. intensive activity was initiated by several national and international standards organizations, including the international organization for standardization (iso). in 1978 the "reference model of open systems interconnection" [8] was produced, and this led to the 1981 draft international standard 7498 "data processing. open systems interconnection - basic reference model" [2]. the documents assume an environment of systems which make themselves "open" to the exchange of data with other systems by adhering to a well-defined set of standard procedures for communication. the documents scope includes not only the basic transfer of information between such systems, but also the capability of such systems to work together in support of distributed applications.  leslie jill miller
evaluation of the wm architecture  this report describes the results of studies of the wm architecture---its performance, the values of some of its key architectural parameters, the difficulty of compiling for it, and hardware implementation complexity. the studies confirm that, with comparable chip area and without heroic compiler technology, wm is capable of outperforming traditional scalar architectures by factors of 2-9. they also underscore the need to devise higher bandwidth memory systems.  wm. a. wulf
dynamic adaptive windows for high speed data networks: theory and simulations  recent results on the asymptotically optimal design of sliding windows for virtual circuits in high speed, geographically dispersed data networks in a stationary environment are exploited here in the synthesis of algorithms for adapting windows in realistic, non-stationary environments. the algorithms proposed here require each virtual circuit's source to measure the round trip response times of its packets and to use these measurements to dynamically adjust its window. our design philosophy is quasi-stationary: we first obtain, for a complete range of parameterized stationary conditions, the relation, called the "design equation", that exists between the window and the mean response time in asymptotically optimal designs; the adaptation algorithm is simply an iterative algorithm for tracking the root of the design equation as conditions change in a non- stationary environment. a report is given of extensive simulations of networks with data rates of 45 mbps and propagation delays of up to 47 msecs. the simulations generally confirm that the realizations of the adaptive algorithms give stable, efficient performance and are close to theoretical expectations when these exist.  d. mitra j. b. seery
a binary feedback scheme for congestion avoidance in computer networks with a connectionless network layer  we propose a scheme for congestion avoidance in networks using a connectionless protocol at the network layer. the scheme uses feedback from the network to the users of the network. the interesting challenge for the scheme is to use a minimal amount of feedback (one bit in each packet) from the network to adjust the amount of traffic allowed into the network. the servers in the network detect congestion and set a congestion indication bit on packets flowing in the forward direction. the congestion indication is communicated back to the users through the transport level acknowledgement.  the scheme is distributed, adapts to the dynamic state of the networks, converges to the optimal operating point, is quite simple to implement, and has low overhead while operational. the scheme also addresses a very important aspect of fairness in the service provided to the various sources utilizing the network. the scheme attempts to maintain fairness in service provided to multiple sources.  this paper presents the scheme and the analysis that went into the choice of the various decision mechanisms. we also address the performance of the scheme under transient changes in the network and for pathological conditions.  k. k. ramakrishnan r. jain
scoped hybrid automatic repeat request with forward error correction (sharqfec) reliable multicast protocols scale only as well as their ability to localize traffic. this is true for repair requests, repairs, and the session traffic that enables receivers to suppress extraneous requests and repairs. we propose a new reliable multicast traffic localization technique called scoped hybrid automatic repeat request with forward error correction (sharqfec). sharqfec operates in an end-to-end fashion and localizes traffic using a hierarchy of administratively scoped regions. session traffic is further reduced through the use of a novel method for indirectly determining the distances between session members. for large sessions, this mechanism reduces the amount of session traffic by several orders of magnitude over non-scoped protocols such as scalable reliable multicast (srm). forward error correction is selectively added to regions which are experiencing greater loss, thereby reducing the volume of repair traffic and recovery times. receivers request additional repairs as necessary. simulations show that sharqfec out performs both srm and non-scoped hybrid automatic repeat request / forward error correction protocols. assuming the widespread deployment of administrative scoping, sharqfec could conceivably provide scalable reliable delivery to tens of millions of receivers without huge increases in network bandwidth. roger g. kermode
performance analysis of fddi token ring networks: effect of parameters and guidelines for setting ttrt  fiber-distributed data interface (fddi) is a 100-mbps local area network (lan) standard being developed by the american national standards institute (ansi). it uses a timed-token access method and allows up to 500 stations to be connected with a total fiber length of 200 km.  we analyze the performance of fddi using a simple analytical model and a simulation model. the performance metrics of response time, efficiency, and maximum access delay are considered. the efficiency is defined as the ratio of maximum obtainable throughput to the nominal bandwidth of the network. the access delay is defined as the time it takes to receive a usable token.  the performance of fddi depends upon several workload parameters; for example; the arrival pattern, frame size, and configuration parameters, such as the number of stations on the ring, extent of the ring, and number of stations that are waiting to transmit. in addition, the performance is affected by a parameter called the target token rotation time (ttrt), which can be controlled by the network manager. we considered the effect of ttrt on various performance metrics for different ring configurations, and concluded that a ttrt value of 8 ms provides a good performance over a wide range of configurations and workloads.  r. jain
the impact of multicast layering on network fairness many definitions of fairness for multicast networks assume that sessions are single-rate, requiring that each multicast session transmits data to all of its receivers at the same rate. these definitions do not account for multi-rate approaches, such as layering, that permit receiving rates within a session to be chosen independently. we identify four desirable fairness properties for multicast networks, derived from properties that hold within the max-min fair allocations of unicast networks. we extend the definition of multicast max-min fairness to networks that contain multi-rate sessions, and show that all four fairness properties hold in a multi-rate max-min fair allocation, but need not hold in a single-rate max-min fair allocation. we then show that multi-rate max-min fair rate allocations can be achieved via intra-session coordinated joins and leaves of multicast groups. however, in the absence of coordination, the resulting max-min fair rate allocation uses link bandwidth inefficiently, and does not exhibit some of the desirable fairness properties. we evaluate this inefficiency for several layered multi-rate congestion control schemes, and find that, in a protocol where the sender coordinates joins, this inefficiency has minimal impact on desirable fairness properties. our results indicate that sender-coordinated layered protocols show promise for achieving desirable fairness properties for allocations in large-scale multicast networks. dan rubenstein jim kurose don towsley
the use of broadcast techniques on the universe network  the universe network is being used to explore broadcasting techniques in a highly integrated computer communications experiment connecting local area networks via a broadcast satellite channel. the broadcast protocol which has been devised within the project provides a versatile framework in which different types of broadcast applications can be carried out. the requirements and definition of this protocol are described, and details are given of how the broadcast satellite channel is used and the implementation of the protocols in the system which provides satellite access from each site. experimental use of the protocol is also described, in particular its use for file distribution. the paper also aims to show how the protocols could be used for more advanced applications.  a. gillian waters christopher j. adams ian m. leslie roger m. needham
an analysis of language models for high-performance communication in local- area networks  in this paper we present an empirical analysis of language models for communication in distributed systems. we consider a computing environment in which a high-level, distributed programming language kernel is sufficient support for high-performance programming applications. we propose programming language support for such an environment and present the performance results of an implementation.  using the distributed programming language starmod as a context, we describe language constructs for message-based communication (including broadcast), remote invocation, and remote memory references. each form of communication is integrated into starmod in a consistent fashion maintaining the properties of transparency, modularity, and full parameter functionality. the costs and benefits associated with the various models of communication are analyzed based on the results of an implementation which runs on 8 pdp 11/23; microprocessors connected by a 1 megabit/second network.  thomas j. leblanc robert p. cook
forward error control for mpeg-2 video transport in a wireless atm lan  the possibility of providing multimedia services to mobile users has led to interest in designing broadband wireless networks that can guarantee quality of service for traffic flows. however, a fundamental problem in these networks is that severe losses may occur due to the random fading characteristics of the wireless channel. error control algorithms which compensate for these losses are required in order to achieve reasonable loss rates. in this paper, the performance of error control based on forward error correction (fec) for mpeg-2 video transmission in an indoor wireless atm lan is studied. arandombit error model and a multipath fading model are used to investigate the effect of errors on video transport. combined source and channel coding techniques that employ single-layer and scalable mpeg-2 coding to combat channel errors are compared. simulation results indicate that fec- based error control in combination with 2-layer video coding techniques can lead to acceptable quality for indoor wireless atm video.  ender ayanoglu pramod pancha amy r. reibman shilpa talwar
smooth migration from the gsm system to umts for multimedia services  third generation of mobile systems is now entering the operational phase; european community acts (race follow-on) programme just aims at finalizing the plenty of solutions resulting from the european community race programme as well as from several other studies and researches. european manufactures, also deeply involved in the acts programme, seem to show a preference for solutions which gradually upgrade the present pan-european gsmsuccessful standard. the underlying concept is the one of a smooth migration from the gsm network to the third generation system, in order to reuse, at least in the first phases of the transition, most of the existing technologies and infrastructures already implemented for the gsm network. in this respect, this paper, by referring to radio interface aspects, proposes a two step evolution: in the first step, a dynamic channel allocation (dca) strategy with distributed control should be implemented for coping with the high variance of traffic entailed by the reduction of cell dimensions; in the second step, a gradual upgrading of the gsmbase stations should allow a smooth transition towards the third generation packet reservation multiple access (prma) technique and the provision of broadband services. the paper is partly based upon the work performed by the author in the framework of the race project "satellite integration in the future mobile network (saint)" and of the european community acts projects median. the opinions herewith reported are not necessarily those of the european community.  francesco delli priscoli
a data request scheduling policy for pcs networks  this paper proposes a scheduling policy called latest preempted, earliest resumed (lper) for personal communications services (pcs) systems that support voice services as well as the circuit mode data services. the policy gives priority to the voice services over the data services. the scheduling of voice requests is performed as if no data requests exist. thus, if no idle channel is available when a voice request arrives, a data channel (if exists) is interrupted and the channel will be used for the voice request. the interrupted data request will be resumed when an idle channel is available. in lper, the data channel selected for interruption is the one that serves the latest outstanding data request (i.e., other outstanding requests enter the system earlier than this request). when an occupied channel is released, lper resumes the earliest request that entered the system. an analytic model is proposed to study the performance of lper and provides guidelines to select the input parameters for the pcs systems.  wen-nung tsai yi-bing lin
the ipsc/2 direct-connect communications technology  this paper describes the hardware architecture and protocol of the message routing system used in the ipsc®/2 concurrent computer. the direct-connect router was developed by intel scientific computers to replace the store-and- forward message passing mechanism used in the original ipsc system. the router enhances the performance of the ipsc/2 system by reducing the message passing latency, increasing the node-to-node channel bandwidth and allowing simultaneous bi-directional message traffic between any two nodes. the new communication system has nearly equal performance between any pair of processing nodes, making the network topology more transparent to the user.  the direct-connect router is a specialized self- contained hardware module attached to each hypercube node. the router is implemented in cmos programmable gate-arrays with advanced cmos buffering. routers are connected by full-duplex bit-serial channels to form a boolean n-cube network. the router also provides a high performance interface between the node memory bus and the network.  s. f. nugent
efficient at-most-once messages based on synchronized clocks  this paper describes a new message passing protocol that provides guaranteed detection of duplicate messages even when the receiver has no state stored for the sender. it also discusses how to use these messages to implement higher- level primitives such as at-most-once remote procedure calls and sequenced bytestream protocols, and describes an implementation of at-most-once rpcs using our method. our performance measurements indicate that at-most-once rpcs can be provided at the same cost as less desirable rpcs that do not guarantee at-most-once execution. our method is based on the assumption that clocks throughout the system are loosely synchronized. modern clock synchronization protocols provide good bounds on clock skew with high probability; our method depends on the bound for performance but not for correctness.  b. liskov l. shrira j. wroclawski
limits on multiple instruction issue  this paper investigates the limitations on designing a processor which can sustain an execution rate of greater than one instruction per cycle on highly- optimized, non-scientific applications. we have used trace-driven simulations to determine that these applications contain enough instruction independence to sustain an instruction rate of about two instructions per cycle. in a straightforward implementation, cost considerations argue strongly against decoding more than two instructions in one cycle. given this constraint, the efficiency in instruction fetching rather than the complexity of the execution hardware limits the concurrency attainable at the instruction level.  m. d. smith m. johnson m. a. horowitz
locating nearby copies of replicated internet servers in this paper we consider the problem of choosing among a collection of replicated servers, focusing on the question of how to make choices that segregate client/server traffic according to network topology. we explore the cost and effectiveness of a variety of approaches, ranging from those requiring routing layer support (e.g., anycast) to those that build location databases using application-level probe tools like traceroute. we uncover a number of tradeoffs between effectiveness, network cost, ease of deployment, and portability across different types of networks. we performed our experiments using a simulation parameterized by a topology collected from 7 survey sites across the united states, exploring a global collection of network time protocol servers. james d. guyton michael f. schwartz
hierarchical performance modeling with macs: a case study of the convex c-240  the macs performance model introduced here can be applied to a machine and application of interest, the compiler-generated workload, and the scheduling of the workload by the compiler. the ma, mac, and macs bounds each fix the named subset of m, a, c, and s while freeing the bound from the constraints imposed by the others. a/x performance measurement is used to measure access- only and execute-only code performance. such hierarchical performance modeling exposes the gaps between the various bounds, the a/x measurements, and the actual performance, thereby focusing performance optimization at the appropriate levels in a systematic and goal-directed manner. a simple, but detailed, case study of the convex c-240 vector mini- supercomputer illustrates the method.  eric l. boyd edward s. davidson
on the interconnection of causal memory systems  a large amount of work has been invested in devising algorithms to implement distributed shared memory (dsm) systems under different consistency models. however, to our knowledge, the possibility of interconnecting dsm systems with simple protocols and the consistency of the resulting system has never been studied. with this paper, we start a series of works on the properties of the interconnection of dsm systems, which tries to fill this void.  in this paper, we look at the interconnection of propagation-based causal dsm systems. we present extremely simple algorithms to interconnect two such systems (possibly implemented with different algorithms), that only require the existence of a bidirectional reliable fifo channel connecting one process from each system. we show that the resulting dsm system is also causal. this result can be generalized to interconnect any number of dsm propagation-based causal systems.  antonio fernández ernesto jimenez vicent cholvi
highly concurrent scalar processing  high speed scalar processing is an essential characteristic of high performance general purpose computer systems. highly concurrent execution of scalar code is difficult due to data dependencies and conditional branches. this paper proposes an architectural concept called guarded instructions to reduce the penalty of conditional branches in deeply pipelined processors. a code generation heuristic, the decision tree scheduling technique, reorders instructions in a complex of basic blocks so as to make efficient use of guarded instructions. performance evaluation of several benchmarks are presented, including a module from the unix kernel. even with these difficult scalar code examples, a speedup of two is achievable by using conventional pipelined uniprocessors augmented by guard instructions, and a speedup of three or more can be achieved using processors with parallel instruction pipelines.  p. y t hsu e. s. davidson
video over tcp with receiver-based delay control  unicasting video streams over tcp connections is a challenging problem because video sources cannot normally adapt to delay and throughput variations of tcp connections. this paper points out a direction on how tcp can be modified such that tcp connections can carry hierarchically-encoded layered video streams well, while being friendly to other competing flows. the method is calledreceiver-based delay control(rdc). under rdc, a tcp connec?n can slow down its transmission rate to avoid congestion by delaying ack packet generation at the tcp receiver based on notifications from routers. the paper presents the principle behind rdc, argue that it is tcp- friendly, describe an implementation that uses 1-bit congestion notification from routers, and give our simulation results.  pai-hsiang hsiao h. t. kung koan-sin tan
dynamic bandwidth management of primary rate isdn to support atm access  one of the principle advantages of asynchronous transfer mode (atm) access is that variable rate streams can be supported efficiently. in order to preserve this efficiency when using atm on an underlying circuit switched network, such as primary rate isdn, flexible control of the underlying circuit bandwidth must be provided. this paper discusses techniques used to provide dynamic management of variable rate circuits to support atm access. models are presented for some of these control schemes and their performance is studied through a combination of simulation and analysis. techniques implemented for an experimental network providing atm access on primary rate isdn are presented.  b. r. harita i. m. leslie
multiuser microcomputer systems  microcomputers are small, efficient, powerful and inexpensive. they have found many uses in commerce and industry as well as for education and enlightenment. they are so inexpensive that it is possible in some firms to put one on everybody's desk. the computers are truly personal.  personal stand-alone computers are fine for doing independent individual work. when it comes to sharing the work of others, we need an integrated system. information created by one person should be easily available to any other person. this is a common policy in education, commerce, industry and engineering where the medium of exchange is the mainframe. terminals allow users access to large quantities of information, as long as they are privileged to do so.  ivan flores