waashk/dblp huggingface dataset:
adaptive leases: a strong consistency mechanism for the world wide web. in this paper, we argue that weak cache consistency mechanisms supported by existing web proxy caches must be augmented by strong consistency mechanisms to support the growing diversity in application requirements. existing strong consistency mechanisms are not appealing for web environments due to their large state space or control message overhead. we focus on the lease approach that balances these trade-offs and present analytical models and policies for determining the optimal lease duration. we present extensions to the http protocol to incorporate leases and, then, implement our techniques in the squid proxy cache and the apache web server. our experimental evaluation of the leases approach shows that 1) our techniques impose modest overheads even for long leases (a lease duration of 1 hour requires state to be maintained for 1,030 leases and imposes an per-object overhead of a control message every 33 minutes), 2) leases yields a 138-425 percent improvement over existing strong consistency mechanisms, and 3) the implementation overhead of leases is comparable to existing weak consistency mechanisms.
an analysis of near optimal call admission and routing model for multi-service loss networks. a state-dependent call admission and routing policy for a multiservice circuit-switched network is analyzed. the policy is based on decomposition of the markov decision problem into a set of separable link problems. to provide an exact link analysis model a value iteration algorithm was offered. this allows examination of the accuracy of several approximations used to reduce the complexity of the problem. the numeral study showed that the convergence of the analyzed strategy is achieved in at most two iterations. the study also showed the good traffic efficiency of the approach and confirmed the predicted ability to control the distribution of call classes grade of service. the approach, together with its sensitivity analysis with respect to the arrival rates, provides a very general framework for studying, constructing, and optimizing other call admission and routing strategies. the results of sensitivity analysis are used to compare the proposed decomposition approach with the decomposition approach developed by f.p. kelly (1988) for optimization of a load sharing policy. also, the relationship to other routing strategies based on markov decision theory is investigated
estimation of aggregate effective bandwidth for traffic admission in atm networks. a framework for adaptive bandwidth management in atm based networks is presented. the central concept of this approach is an adaptive estimation of the aggregate effective bandwidth required by connections carried on each link of the network. to achieve reliable results the estimation process takes into account both the traffic source declarations and the connection superposition process measurements on the network links. this is done in an optimization framework provided by estimation theory. in the paper the authors concentrate on evaluation of a bandwidth reserved for possible estimation error. for this purpose they use the error covariance matrix from a linear two state kalman filter applied for the system state estimation. the bandwidth reserved for the estimation error provides that the source parameter declarations can be more relaxed and that the source policing can be less stringent.
address management and connection control for multicast communication applications. an architecture and associated protocols are presented for managing multicast addresses and performing connection control for multicast communication applications. a scheme to partition the multicast address space on the basis of the network number is proposed (an underlying ip-based internetworking environment is assumed), and its performance and scaling characteristics are discussed. a protocol is then developed to provide for dynamic allocation and release of multicast addresses, as well as maintaining state information for a connection. the protocol is independent of the address partitioning scheme; it is also shown to be robust and efficient. finally, we describe two different mechanisms that enable the use of a common port number by all session participants.
topological design of local area networks using genetic algorithms. continually growing number of users have to exchange increasing amounts of information. local area networks (lans) are commonly used as the communication infrastructure that meets the demands of the users in the local environment. these networks typically consist of several lan segments connected together via bridges. the authors describe an algorithm for designing lans with the objective of minimizing the average network delay. the topology design includes issues such as determination of the number of segments in the network, allocating the users to the different segments and determining the interconnections and routing among the segments. the determination of the optimal lan topology is a complicated combinatorial optimisation problem. therefore, a heuristic algorithm which is based on genetic ideas is used. numerical examples are provided and the quality of the designs obtained by using the algorithm is compared with lower bounds on the average network delay that are developed.
performance evaluation of atm shortcut connections in overlaid ip/atm networks. -------- in this paper we present methods to evaluate the benefit of using direct atm connections (shortcuts) between ip nodes in ip over atm networks, and we evaluate the benefit of atm shortcuts for several networks. we model an ip/atm network with and without atm shortcuts as two loss networks. we propose a metric, the network load ratio, for network performance comparison, that gives the ratio of the number of flows accepted by two networks at the same network blocking probability. we derive an estimator of this metric, the asymptotic load ratio, that has low computational complexity. we use this estimator as a basis for a methodology for network performance comparison, and use it to evaluate the benefit of atm shortcuts in several concrete scenarios.
mate: mpls adaptive traffic engineering. destination-based forwarding in traditional ip routers has not been able to take full advantage of multiple paths that frequently exist in internet service provider networks. as a result, the networks may not operate efficiently, especially when the traffic patterns are dynamic. this paper describes a multipath adaptive traffic engineering scheme, called mate, which is targeted for switched networks such as multiprotocol label switching networks. the main goal of mate is to avoid network congestion by adaptively balancing the load among multiple paths based on measurement and analysis of path congestion. mate adopts a minimalist approach in that intermediate nodes are not required to perform traffic engineering or measurements besides forwarding packets. moreover, mate does not impose any particular scheduling, buffer management, or a priori traffic characterization on the nodes. this paper presents an analytical model, derives a class of mate algorithms, and proves their convergence. several practical design techniques to implement mate are described. simulation results are provided to illustrate the efficacy of mate under various network scenarios.
fluid models for the analysis and design of statistical multiplexing with loss priorities on multiple classes of bursty traffic. the authors give the complete solution for a stochastic fluid model of statistical multiplexing with loss priorities in asynchronous transfer mode (atm)-based broadband isdn. in this model each markov modulated fluid source generates priority and marked cell streams which are bursty, mutually correlated, and periodic during bursts. the output of many such sources is buffered and multiplexed for transmission. the loss priority is implemented by selectively discarding marked cells when the buffer content exceeds a threshold level. the equilibrium state distribution exhibits jumps, a feature not existent in prior fluid models. the computational complexity for two-state sources is dominated by a single system of linear equations of dimension equal to twice the number of sources, in particular, the complexity is independent of buffer size. the complete delay distribution for each traffic class is obtained. numerical results are given. the analysis is generalized to several priority classes of traffic
analysis, approximations and admission control of a multi-service multiplexing system with priorities. we consider an atm system with an architecture which is designed to accommodate users with very different quality of service requirements. sources which belong to a high priority class share a fcfs buffer, which has priority access to the trunk. a low priority class of sources have a separate fcfs buffer, which receives the residual bandwidth, if any. by administering admission control the service guarantees for both classes may be satisfied. the sources are bursty and stochastic fluid models are used to handle burst-scale congestion effects. we develop simple, fast and robust analytic approximations for the queue distributions in the two buffers. we calculate the admissible set by using our analytic approximations and find that it is reasonably accurate and a conservative approximation to the correct set. the key element in our analysis is a characterization of the output of the high priority buffer as another markov-modulated fluid source. a refinement to the now well known effective bandwidth approximation is used to calculate buffer content distributions.
a distributed global queue transmission strategy for a wdm optical fiber network. a new distributed global queueing strategy and medium access protocol that users employ to schedule their transmissions to avoid receiver collisions is introduced for an optical fiber network. the network uses wavelength division multiplexing (wdm) for the data channels. the medium access control utilizes tdma on the control channel to allow users to implement a global reservation scheme to send data packets. the data channels operate under a distributed demand assignment scheme that allows receiver collision-free operation and efficient scheduling. an analytical solution is obtained via equilibrium point analysis (epa). it was shown that the maximum throughput obtained is approximately 42% which exceeds the maximum throughput of aloha based medium access protocols. the delay is shown to be relatively constant for a wide range of operation.
traffic shaping at a network node: theory, optimum design, admission control. this paper develops a framework of traffic shaping which has the goal of increasing the nodal connection-carrying capacity. the shaping filters are designed to interwork with statistical multiplexers which use fifo buffers. differences in delay tolerances between traffic classes are exploited to shape and smooth the less delay sensitive traffic. the source model used in the analysis is asynchronous, worst-case subject to dual leaky bucket regulation, where the asynchrony is due to the assumption of independent sources. this, together with the allowance of small loss probabilities, makes statistical multiplexing feasible.we require the shapers to be lossless so that losses, if any, occur only at the multiplexer. we obtain the optimal design of the shaper such that a given delay tolerance for the connection is satisfied. for purposes of admission control we obtain the admissible region of combinations of sources of various types such that the qos requirements in loss and delay are satisfied. by examining the regions obtained with and without shaping we quantify the capacity gain from shaping. our numerical results show that the gain can be substantial.
xunet 2: a nationwide testbed in high-speed networking. xunet 2 is an experimental wide-area network that serves as a testbed for research on data communications techniques. the authors provide an overview of the architecture of the xunet 2 testbed. xunet 2 has three principal components: routers, switches and network management systems. long-haul transmission between them will initially use ds3 facilities. performance objectives for the backbone have been set to cover a wide range of transmission speeds. each router attaches a local area network to the backbone network. the backbone network provides virtual circuit connectivity between the routers. circuit setup and teardown is done by a control computer associated with each switch, and the network as a whole will be managed by a network management station in the network operations center
optimal energy allocation and admission control for communications satellites. we address the issue of optimal energy allocation and admission control for communications satellites in earth orbit. such satellites receive requests for transmission as they orbit the earth, but may not be able to serve them all, due to energy limitations. the objective is to choose which requests to serve so that the expected total reward is maximized. the special case of a single energy-constrained satellite is considered. rewards and demands from users for transmission (energy) are random and known only at request time. using a dynamic programming approach, an optimal policy is derived and is characterized in terms of thresholds. furthermore, in the special case where demand for energy is unlimited, an optimal policy is obtained in closed form. although motivated by satellite communications, our approach is general and can be used to solve a variety of resource allocation problems in wireless communications.
topological design of interconnected lan-man networks. the authors describe a methodology for designing interconnected local area network/metropolitan area network (lan-man) networks with the objective of minimizing the average network delay. they consider ieee 802.3-5 lans interconnected by transparent bridges. these bridges are required to form a spanning tree topology. the optimization algorithm for finding a minimum delay spanning tree topology is based on simulated annealing. in order to measure the quality of the solutions, a lower bound for the average network delay is found. the comparison of results with this lower bound and several other goodness measures shows that the solutions are not very far from the global minimum. the authors extend the present algorithm for finding minimum delay lan-man topologies consisting of fiber distributed data interface (fddi) mans or switched multi-megabit data service (smds) interconnecting several clusters of bridged lans
fair resource allocation in wireless networks using queue-length-based scheduling and congestion control. we consider the problem of allocating resources (time slots, frequency, power, etc.) at a base station to many competing flows, where each flow is intended for a different receiver. the channel conditions may be time-varying and different for different receivers. it is well-known that appropriately chosen queue-length based policies are throughput-optimal while other policies based on the estimation of channel statistics can be used to allocate resources fairly (such as proportional fairness) among competing users. in this paper, we show that a combination of queue-length-based scheduling at the base station and congestion control implemented either at the base station or at the end users can lead to fair resource allocation and queue-length stability.
an assessment of state and lookup overhead in routers. the current internet is based on a stateless (datagram) architecture. however, many recent proposals rely on the maintenance of state information within network routers, leading to the authors' interest in the implications of a stateful network layer. they collected internetwork traffic traces at the border routers of stub and transit networks, and used these data to evaluate, or predict, the effects of design alternatives for stateful architectures. they present an estimate of the number of active conversations at a router, and from this derive the storage requirements for the associated conversation state table. the analysis shows that, at the network periphery, fine-grain control over the traffic may be possible. however, deeper within the network, it may be more efficient to manage the conversations at a coarser level. the network traffic traces are used to perform trace driven simulations of an lru cache, for different conversation granularities. results show that locality exists for each of the conversation types investigated
delay jitter correlation analysis for traffic transmission on high speed networks. studies the time-dynamic behavior of delay jitter as captured by the autocorrelation function; the second-order statistics provide information relating to consecutive cell loss in real-time services. the authors derive an expression for delay jitter correlation of a stationary traffic stream in an mmpp/m/1/k system with fifo service discipline; use of a type of deterministic rate server yields the same correlation function but with reduced variance. the jitter second-order statistics are shown to depend strongly on those of the queue, and the queue second-order statistics depend strongly on those of the input traffic. the authors show that the shape of the jitter correlation is determined by the weighted difference in queue correlations, and they derive a method for obtaining the weights for an mmpp traffic stream. in the numerical study emphasis is placed on a periodic traffic stream (such as cbr video) multiplexed on a major communication node; the authors investigate the impact of input traffic correlations and queueing system parameters on the queue length and delay jitter second-order statistics. they also briefly consider the delay jitter correlation from a binary markov source (voice model).
an abr feedback control scheme with tracking. we propose an explicit-rate abr feedback control scheme, ut (uniform tracking). the distinct feature of ut is that it achieves max-min fairness by tracking an effective number of sources; specific constraint information is not required. as a result, its implementation is much simpler than that of other fair control schemes; indeed, its complexity is similar to that of *unfair* explicit-rate controls. in the thorough simulation study, ut demonstrates its ability to scale with speed, distance, number of users (both persistent and bursty), and number of switches while remaining robust, efficient, and fair under stressing conditions with mpeg background traffic and multiple propagation delay loops.
a time-wavelength assignment algorithm for a wdm star network. the first time-wavelength assignment algorithm for wavelength division multiplexing (wdm) star-based local and metropolitan area networks is presented. the algorithm incorporates the unique aspects of wdm communication such as a number of tunable transmitters and receivers at each concentrator, the tuning time, and a limited number of wavelengths. the transmission duration is composed of two elements: the packet transmission time, and the overhead incurred due to the tunability of the system's transmitters and receivers. for a given traffic matrix, the algorithm obtains a tdm/wdm schedule with minimal packet transmission duration, while minimizing the tuning time
an optimal establishment of virtual path connections for atm networks. a number of optimization models for the establishment of virtual path connections (vpcs) with reserved capacity have been proposed in the literature. all of them, however, failed to reflect the trade-off between increased capacity costs and reduced control costs explicitly in their formulations. the present authors develop a mathematical formulation for an optimal strategy for the reservation of capacity on vpcs, considering the trade-off between increased capacity costs and reduced control costs. in this formulation, they also consider the reservation of buffers on vpcs. algorithms and numerical results are presented.
fitting mixtures of exponentials to long-tail distributions to analyze network performance models. traffic measurements from communication networks have shown that many quantities characterizing network performance have long-tail probability distributions, i.e., with tails that decays more slowly than exponentially. long-tail distributions can have a dramatic effect upon performance, but it is often difficult to describe this effect in detail, because performance models with component long-tail distributions tend to be difficult to analyze. we address this problem by developing an algorithm for approximating a long-tail distribution by a finite mixture of exponentials. the fitting algorithm is recursive over time scales. at each stage, an exponential component is fit in the largest remaining time scale and then the fitted exponential component is subtracted from the distribution. even though a mixture of exponentials has an exponential tail, it can match a long-tail distribution in the regions of primary interest when there are enough exponential components.
efficient admission control for edf schedulers. in this paper we present algorithms for flow admission control at an edf link scheduler when the flows are characterized by peak rate, average rate and burst size. we show that the algorithms have very low computational complexity and are easily applicable in practice. the complexity can be further decreased by introducing the notion of flex classes. we evaluate the penalty in efficiency that the classes incur to the edf scheduler. we find that this efficiency degradation can be made arbitrarily small and is acceptable even for a small number of classes.
crankback prediction in hierarchical atm networks. when an atm node discovers that it cannot continue the setup of a virtual channel under the requested quality of service (qos), it initiates a backtracking procedure called &ldquo;crankback.&rdquo; we propose a novel scheme, referred to as crankback prediction, that decreases the crankback overhead. under the proposed scheme, nodes check during the connection admission control procedure whether the establishment of a virtual channel has a good chance to be admitted over the entire designated route. if this is not the case, crankback is initiated even before a particular qos parameter is violated. the main idea behind the proposed scheme is to allocate a &ldquo;quota&rdquo; to the peer groups (pgs) along the message path, and then to suballocate this quota to the child pgs of these pgs. this process continues recursively until reaching the 1-level pg, which contains only physical nodes. the main advantage of the proposed scheme is that it lowers the setup delay and the processing and communication load imposed by signaling messages that establish unused portions of virtual channels (vcs)