waashk/acm huggingface dataset:
efficient support of delay and rate guarantees in an internet in this paper, we investigate some issues related to the efficient provision of end-to-end delay guarantees in the context of the guaranteed (g) services framework [16]. first, we consider the impact of reshaping traffic within the network on the end-to-end delay, the end-to-end jitter, as well as per-hop buffer requirements. this leads us to examine a class of traffic disciplines that use reshaping at each hop, namely rate-controlled disciplines. in this case, it is known that it is advantageous to use the earliest deadline first (edf) scheduling policy at the link scheduler [8]. for this service discipline, we determine the appropriate values of the parameters that have to be exported, as specified in [16]. subsequently, with the help of an example, we illustrate how the g service traffic will typically underutilize the network, regardless of the scheduling policy used. we then define a guaranteed rate (gr) service, that is synergetic with the g service framework and makes use of this unutilized bandwidth to provide rate guarantees to flows. we outline some of the details of the gr service and explain how it can be supported in conjunction with the g service in an efficient manner. l. georgiadis r. guerin v. peris r. rajan
the performance of cache-coherent ring-based multiprocessors  advances in circuit and integration technology are continuously boosting the speed of microprocessors. one of the main challenges presented by such developments is the effective use of powerful microprocessors in shared memory multiprocessor configurations. we believe that the interconnection problem is not solved even for small scale shared memory multiprocessors, since the speed of shared buses is unlikely to keep up with the bandwidth requirements of new microprocessors. in this paper we evaluate the performance of unidirectional slotted ring interconnection for small to medium scale shared memory systems, using a hybrid methodology of analytical models and trace-driven simulations. we evaluate both snooping and directory-based coherence protocols for the ring and compare it to high performance split transaction buses.  luis andre barroso michel dubois
critical path analysis of tcp transactions  improving the performance of data transfers in the internet (such as web transfers) requires a detailed understanding of when and how delays are introduced. unfortunately, the complexity of data transfers like those using http is great enough that identifying the precise causes of delays is difficult. in this paper we describe a method for pinpointing where delays are introduced into applications like http by using critical path analysis. by constructing and profiling the critical path, it is possible to determine what fraction of total transfer latency is due to packet propagation, network variation (e.g., queuing at routers or route fluctuation), packet losses, and delays at the server and at the client. we have implemented our technique in a tool called tcpeval that automates critical path analysis for web transactions. we show that our analysis method is robust enough to analyze traces taken for two different tcp implementations (linux and freebsd). to demonstrate the utility of our approach, we present the results of critical path analysis for a set of web transactions taken over 14 days under a variety of server and network conditions. the results show that critical path analysis can shed considerable light on the causes of delays in web transfers, and can expose subtleties in the behavior of the entire end-to-end system.  paul barford mark crovella
wide-area traffic: the failure of poisson modeling  network arrivals are often modeled as poisson processes for analytic simplicity, even though a number of traffic studies have shown that packet interarrivals are not exponentially distributed. we evaluate 21 wide-area traces, investigating a number of wide-area tcp arrival processes (session and connection arrivals, ftpdata connection arrivals within ftp sessions, and telnet packet arrivals) to determine the error introduced by modeling them using poisson processes. we find that user-initiated tcp session arrivals, such as remote-login and file- transfer, are well-modeled as poisson processes with fixed hourly rates, but that other connection arrivals deviate considerably from poisson; that modeling telnet packet interarrivals as exponential grievously underestimates the burstiness of telnet traffic, but using the empirical tcplib[djcme92] interarrivals preserves burstiness over many time scales; and that ftpdata connection arrivals within ftp sessions come bunched into "connection burst", the largest of which are so large that they completely dominate ftpdata traffic. finally, we offer some preliminary results regarding how our findings relate to the possible self- similarity of wide-area traffic.  vern paxson sally floyd
enhancing boosting with semantic register in a superscalar processor (abstract)  ias-s supports boosting with "semantic register" and boosting boundary register to remove the dependences caused by conditional branches. in ias-s, there is no dedicated shadow register file, and multiple levels of boosting is supported without multiple copies of register files. any general-purpose register in ias-s can be regarded as a sequential register or a shadow register flexibly. furthermore, multi-way jump mechanism is combined with boosting to reduce the penalty due to frequent control transfers.  feipei lai meng-chou chang
location dependent query processing  the advances in wireless and mobile computing allow a mobile user to perform a wide range of aplications once limited to non-mobile hard wired computing environments. as the geographical position of a mobile user is becoming more trackable, users need to pull data which are related to their location, perhaps seeking information about unfamiliar places or local lifestyle data. in these requests, a location attribute has to be identified in order to provide more efficient access to location dependent data, whose value is determined by the location to which it is related. local yellow pages, local events, and weather information are some of the examples of these data.  in this paper, we give a formalization of location relatedness in queries. we differentiate location dependence and location awareness and provide thorough examples to support our approach.  ayse y. seydim margaret h. dunham vijay kumar
using value prediction to increase the power of speculative execution hardware  this article presents an experimental and analytical study of value prediction and its impact on speculative execution in superscalar microprocessors. value prediction is a new paradigm that suggests predicting outcome values of operations (at run-time ) and using these predicted values to trigger the execution of true-data-dependent operations speculatively. as a result, stals to memory locations can be reduced and the amount of instruction-level parallelism can be extended beyond the limits of the program's dataflow graph. this article examines the characteristics of the value prediction concept from two perspectives: (1) the related phenomena that are reflected in the nature of computer programs and (2) the significance of these phenomena to boosting instruction-level parallelism of superscalar microprocessors that support speculative execution. in order to better understand these characteristics, our work combines both analytical and experimental studies.  freddy gabbay avi mendelson
development of the domain name system 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. paul v. mockapetris kevin j. dunlap
architecture and experimental results for quality of service in mobile networks using rsvp and cbq  efforts are underway to enhance the internet with quality of service qos capabilities for transporting real - time data. the issue of wireless networks and mobile hosts being able to support applications that require qos has become very significant. the reservation protocol rsvp provides a signaling mechanism for end - to - end qos negotiation. rsvp has been designed to work with wired networks. to make rsvp suitable for wireless networks, changes need to be made by i changing the way control messages are sent, and ii introducing wireless/mobile specific qos parameters that take into account the major features of wireless networks, namely, high losses, low bandwidth, power constraints and mobility. in this paper, an architecture with a modified rsvp protocol that helps to provide qos support for mobile hosts is presented. the modified rsvp protocol has been implemented in an experimental wireless and mobile testbed to study the feasibility and performance of our approach. class based queueing cbq which is used as the underlying bandwidth enforcing mechanism is also modified to fit our approach. the experimental results show that the modified rsvp and cbq help in satisfying resource requests for mobile hosts, after handoff occurs. the experiments also show how different power and loss profile mechanisms can be used with our framework. the system performance using the modified rsvp control mechanism is also studied.  indu mahadevan krishna m. sivalingam
probabilistic diagnosis of multiprocessor systems  this paper critically surveys methods for the automated probabilistic diagnosis of large multiprocessor systems. in recent years, much of the work on system-level diagnosis has focused on probabilistic methods, which can diagnose intermittently faulty processing nodes and can be applied in general situations on general interconnection networks. the theory behind the probabilistic diagnosis methods is explained, and the various diagnosis algorithms are described in simple terms with the aid of a running example. the diagnosis methods are compared and analyzed, and a chart is produced, showing the comparative advantages of the various diagnosis algorithms on the basis of several factors important to the probabilistic diagnosis.  sunggu lee kang geun shin
mobility management for hierarchical wireless networks  in this paper, we consider the mobility management in large, hierarchically organized multihop wireless networks. the examples of such networks range from battlefield networks, emergency disaster relief and law enforcement etc. we present a novel netwroks addressing architecture to accommodate mobility using a "home agent" concept akin to mobile ip. we distinguish between the "physical" routing hierarchy (dictated by geographical relationships between nodes) and "logical" hierarchy of subnets in which the members moves as a group (e.g., company, brigade, abttalion in the battlefield). the performance of the mobility management scheme is investigated through simulation.  guangyu pei mario gerla
a communication structure for a multiprocessor computer with distributed global memory  an experimental multiprocessor computer was designed and built in order to explore the feasibility of certain internal communication mechanisms. the system consisted of seven processing elements, each containing a part of the global memory connected to a local bus. for each processor the global memory is seen as one single, linearly addressable structure. the processing elements were all connected to a common, global bus, consisting of three separate busses in order to increase the capacity. a bus selection unit was designed, capable of making a unique bus selection for each request, within a fraction of a memory cycle. the experiments have shown that communication structures based on distributed global memory and global bus systems can be used efficiently for medium scale systems.  lars philipson bo nilsson bjorn breidegard
wireless atm - an overview  this paper sketches the requirements and possibilities of wireless atm in local area networks. because of the wide range of services supported by atm networks, atm technology is expected to become the dominant networking technology in the mediumtermfor both public infrastructure networks and for local area networks. atm infrastructure can support all types of services, from time-sensitive voice communications and desk-top multi-media conferencing, to bursty transaction processing and lan traffic. extending the atm infrastructure with a wireless access mechanismmeets the needs of those users and customers that want a unified, end-to-end networking infrastructure with high-performance, consistent service characteristics. the paper introduces atm concepts, discusses the requirements for wireless atm, in particular for data link control and radio functions. it closes with some notes on development of wireless atm research systems standardization and spectrum allocations.  geert a. awater jan kruys
renaming in an asynchronous environment  this paper is concerned with the solvability of the problem of processor renaming in unreliable, completely asynchronous distributed systems. fischer et al. prove in [8] that "nontrivial consensus" cannot be attained in such systems, even when only a single, benign processor failure is possible. in contrast, this paper shows that problems of processor renaming can be solved even in the presence of up to t < n/2 faulty processors, contradicting the widely held belief that no nontrivial problem can be solved in such a system. the problems deal with renaming processors so as to reduce the size of the initial name space. when only uniqueness of the new names is required, we present a lower bound of n \\+ 1 on the size of the new name space, and a renaming algorithm that establishes an upper bound on n \\+ t. if the new names are required also to preserve the original order, a tight bound of 2′(n \\- t \\+ 1) - 1 is obtained.  hagit attiya amotz bar-noy danny dolev david peleg rudiger reischuk
interaction of tcp and data access control in an integrated voice/data cdma system  this paper considers the interaction between a proposed data access control scheme and the standardized error recovery schemes on the radio link of a voice/data cdma system. a data access control scheme for combined voice-data cdma systems has been proposed and studied in previous literature. the scheme aims to maintain a certain target voice signal to interference ratio (sir); this is achieved by controlling the data load according to the measured voice sir. the data users are allowed to transmit in a radio-link time slot with a certain permission probability, which is determined by the base station based on the measured voice sir in the previous slot. as per the is-99 standards, however, data transmission operates under the framework of tcp, which is a higher level end-to-end protocol. the tcp data unit, called a segment, is typically equivalent to several tens of physical layer frames; hence, a segment transmission takes up several tens of slots. due to changes in the number of voice users in talkspurt (which occur on a time scale shorter than a segment transmission time), the slot level data access control scheme can introduce significant variability in the segment transmission time. the effect of such variability on the tcp timers, which operate at the segment level, is of interest. in this paper, an approximate upper bound on the data throughput, taking the presence of tcp into account, is computed. the results provide one with an insight into the interaction of the access control scheme with tcp; they also give practical pointers as to choosing suitable parameters and operating points for the scheme.  sudhir ramakrishna jack m. holtzman
execution control and memory management of a data flow signal processor  the architecture of the data flow signal processor (dfsp) is discussed with the emphasis on its control mechanism. it is argued that the data flow principle can be efficiently applied to block processing operations of nonrecursive dsp computations, when shared data structures are avoided. simulation results involving the optimal operand size and the memory use of the control section are presented. due to the expandability and convenient programmability of the dfsp architecture, the range of its potential applications extends beyond signal processing as demonstrated by a dfsp based database machine.  klaus kronlöf
secure and mobile networking  the ietf mobile ip protocol is a significant step towards enabling nomadic internet users. it allows a mobile node to maintain and use the same ip address even as it changes its point of attachment to the internet. mobility implies higher security risks than static operation. portable devices may be stolen or their traffic may, at times, pass through links with questionable security characteristics. most commercial organizations use some combination of source-filtering routers, sophisticated firewalls, and private address spaces to protect their network from unauthorized users. the basic mobile ip protocol fails in the presence of these mechanisms even for authorized users. this paper describes enhancements that enable mobile ip operation in such environments, i.e., they allow a mobile user, out on a public portion of the internet, to maintain a secure virtual presence within his firewall-protected office network. this constitutes what we call a mobile virtual private network (mvpn).  vipul gupta gabriel montenegro
stability of long-lived consensus (extended abstract)  this paper introduces the notion stability for a long-lived consensus system. this notion reflects how sensitive to changes the decisions of the system are, from one invocation of the consensus algorithm to the next, with respect to input changes. stable long-lived consensus systems are proposed, and tight lower bounds on the achievable stability are proved, for several different scenarios. the scenarios include systems that keep memory from one invocation of consensus to the next versus memoryless systems; systems that take their decisions based on the number of different inputs but not on the source identities of those inputs versus non-symmetric systems. these results intend to study essential aspects of stability, and hence are independent of specific models of distributed computing. applications to particular asynchronous and synchronous system are described.  shlomi dolev sergio rajsbaum
an energy consumption model for performance analysis of routing protocols for mobile ad hoc networks  a mobile ad hoc network (or manet) is a group of mobile, wireless nodes which cooperatively form a network independent of any fixed infrastructure or centralized administration. in particular, a manet has no base stations: a node communicates directly with nodes within wireless range and indirectly with all other nodes using a dynamically-computed, multi- hop route via the other nodes of the manet.  simulation and experimental results are combined to show that energy and bandwidth are substantively different metrics and that resource utilization in manet routing protocols is not fully addressed by bandwidth-centric analysis. this report presents a model for evaluating the energy consumption behavior of a mobile ad hoc network. the model was used to examine the energy consumption of two well- known manet routing protocols. energy-aware performance analysis is shown to provide new insights into costly protocol behaviors and suggests opportunities for improvement at the protocol and link layers.  laura marie feeney
optimal distributed location management in mobile networks  an important issue in the design of future personal communication services (pcs) networks is the efficient management of location information. in this paper, we consider a distributed database architecture for location management in which update and query loads of the individual databases are balanced. we obtain lower bounds to the worst-case delay in locating a mobile user, to the average delay, and to the call blocking probability. we then propose a dynamic location management algorithm that meets these lower bounds. the optimality of this algorithm with respect to these three perofrmance measures, as well as simplicity, make it an appealing candidate for distributed location management in pcs networks.  govind krishnamurthi murat azizoglu arun k. somani
collection and analysis of data from communication system networks  this paper provides a brief overview of a new, limited and specific direction in the study of computer-based information systems: the study of communication networks by means of computer-monitored usage and content. this area of research is the result of the interaction of two foci in recent research: (1) the increasing use of computer-mediated communication systems in organizations, and (2) the conceptualization of communication as a process of convergence, or networks of relations.  ronald e. rice
fragmentation considered harmful internetworks can be built from many different kinds of networks, with varying limits on maximum packet size. throughput is usually maximized when the largest possible packet is sent; unfortunately, some routes can carry only very small packets. the ip protocol allows a gateway to _fragment_ a packet if it is too large to be transmitted. fragmentation is at best a necessary evil; it can lead to poor performance or complete communication failure. there are a variety of ways to reduce the likelihood of fragmentation; some can be incorporated into existing ip implementations without changes in protocol specifications. others require new protocols, or modifications to existing protocols. christopher a. kent jeffrey c. mogul
hierarchical function distribution - a design principle for advanced multicomputer architectures  an abstract view of a computer system is provided by a hierarchy of functions, ranging from the high-level operating system functions down to the primitive functions of the hardware. vertical migration of high-level functions into the microcode of a cpu or horizontal migration of hardware functions out of the cpu into dedicated processors alone is not an adequate realization method for innovative computer architectures with complex functionality. in the paper, a new design principle called hierarchical function distribution is introduced to cope with the task of designing innovative multicomputer systems with complex functionality. the design rules of hierarchical function distribution are presented, and the advantages of the approach are discussed and illustrated by examples.  w. k. giloi p. behr