waashk/acm huggingface dataset:
a model for enhancing connection rerouting in mobile networks in active networks (ans) programs can be injected into routers and switches to extend the functionalities of the network. this allows programmers to enhance existing protocols and enables the rapid deployment of new protocols. the main objective of this paper is to show why ans are ideal in solving the problem of connection rerouting and how current end-to-end based approaches can be enhanced. in this paper we propose a new model called active connection rerouting (acr). in the acr model, programs are dynamically injected into switches/routers in mobile networks to facilitate efficient connection rerouting during mobile host (mh) migration. we show how connection rerouting can be performed efficiently within the network. the acr model uses a two stage optimization process: (i) path extension and (ii) lazy optimization. unlike previous work on two stage connection rerouting acr has the following properties: elimination of loops within switches/routers and incremental optimization which minimizes buffer requirements and maximized path reuse. acr performs well in all topologies. our experimental results show that acr is efficient and scalable and it performs well in all topologies.
power and energy reduction via pipeline balancing  _minimizing power dissipation is an important design requirement for both portable and non-portable systems. in this work, we propose an architectural solution to the power problem that retains performance while reducing power. the technique, known as_ pipeline balancing (plb), _dynamically tunes the resources of a general purpose processor to the needs of the program by monitoring performance within each program. we analyze metrics for triggering_ plb, _and detail instruction queue design and energy savings based on an extension of the alpha 21264 processor. using a detailed simulator, we present component and full chip power and energy savings for single and multi-threaded execution. results show an issue queue and execution unit power reduction of up to 23% and 13%, respectively, with an average performance loss of 1% to 2%_.  r. iris bahar srilatha manne
an approach to scalability study of shared memory parallel systems  the overheads in a parallel system that limit its scalability need to be identified and separated in order to enable parallel algorithm design and the development of parallel machines. such overheads may be broadly classified into two components. the first one is intrinsic to the algorithm and arises due to factors such as the work-imbalance and the serial fraction. the second one is due to the interaction between the algorithm and the architecture and arises due to latency and contention in the network. a top-down approach to scalability study of shared memory parallel systems is proposed in this research. we define the notion of overhead functions associated with the different algorithmic and architectural characteristics to quantify the scalability of parallel systems; we isolate the algorithmic overhead and the overheads due to network latency and contention from the overall execution time of an application; we design and implement an execution-driven simulation platform that incorporates these methods for quantifying the overhead functions; and we use this simulator to study the scalability characteristics of five applications on shared memory platforms with different communication topologies.  anand sivasubramaniam aman singla umakishore ramachandran h. venkateswaran
a threaded/flow approach to reconfigurable distributed systems and service primitives architectures  this paper discusses a methodology for managing the assembly, control, and disassembly of large numbers of independent small-scale configurations within large-scale reconfigurable distributed systems. the approach is targeted at service primitives architectures for enhanced telecommunications networks, but can apply to more general settings such as multi-tasking supercomputers and network operations systems.* study of the methods presented here was a key motivation in founding the bell communications research integrated media architecture laboratory (imal) [1].  the threaded/flow approach uses data- flow constructs to assemble higher level functions from other distributed functions and resources with arbitrary degrees of decentralization. equivalence between algorithms and hard and virtual resources is accomplished via threaded-interpretive constructs. function autonomy, concurrency, conditional branching, pipelining, and setup/execution interaction are implicitly supported. some elementary performance comparisons are argued.  this work is motivated by telecommunications applications involving coordinated multiple-media in open architectures supporting large numbers of users and outside service vendors. in such networks it is desired that services may be flexibly constructed by the network, service vendors, or by users themselves from any meaningful combination of elementary primitives and previously defined services. reliability, billing, call progress, real-time user control, and network management functions must be explicitly supported. these needs are handled with apparent high performance by the approach.  l. f. ludwig
a study of branch prediction strategies  in high-performance computer systems, performance losses due to conditional branch instructions can be minimized by predicting a branch outcome and fetching, decoding, and/or issuing subsequent instructions before the actual outcome is known. this paper discusses branch prediction strategies with the goal of maximizing prediction accuracy. first, currently used techniques are discussed and analyzed using instruction trace data. then, new techniques are proposed and are shown to provide greater accuracy and more flexibility at low cost.  james e. smith
protocol implementation using integrated layer processing integrated layer processing (ilp) is an implementation concept which "permit[s] the implementor the option of performing all the [data] manipulation steps in one or two integrated processing loops" [1]. to estimate the achievable benefits of **ilp** a file transfer application with an encryption function on top of a user-level tcp has been implemented and the performance of the application in terms of throughput and packet processing times has been measured. the results show that it is possible to obtain performance benefits by integrating marshalling, encryption and tcp checksum calculation. they also show that the benefits are smaller than in simple experiments, where ilp effects have not been evaluated in a complete protocol environment. simulations of memory access and cache hit rate show that the main benefit of ilp is reduced memory accesses rather than an improved cache hit rate. the results further show that data manipulation characteristics may significantly influence the cache behavior and the achievable performance gain of ilp. torsten braun christophe diot
optimizing video-on-demand through requestcasting  video-on-demand (vod) designs typically feature either request or broadcast architectures. both have limitations. request architectures experience a limit in the number of clients that can be adequately serviced. broadcast architectures require large, often unavailable, bandwidth. in addition, it is difficult to limit viewing to a target audience. in this paper, we present a new architecture for a metropolitan vod service that we name requestcasting. our architecture combines the two general approaches of request and broadcast, but not their respective limitations. with the requestcast architecture, we implement an improved pyramid broadcasting protocol. our synchronized method of employing pyramid broadcasting is key to providing robust vod service.  julie pochueva ethan v. munson denis pochuev
reliability and performance of hierarchical raid with multiple controllers  redundant arrays of inexpensive disks (raid) offer fault tolerance against disk failures. however a storage system having more disks suffers from less reliability and performance. a raid architecture tolerating multiple disk failures shows severe performance degradation in comparison to the raid level 5 due to the complexity of implementation. we present a new raid architecture that tolerates at least three disk failures and offers similar throughout to the raid level 5. we call it the hierarchical raid, which is hierarchically composed of raid levels. furthermore, we formally introduce the mean-time-to- data-loss (mttdl) of traditional raid and the hierarchical raid using markov process for detailed comparison.  sung hoon baek bong wan kim eui joung joung chong won park
performance analysis of an asynchronous multi-rate crossbar with bursty traffic  one of the most promising approaches to building high speed networks and distributed multiprocessors is the use of optical interconnections. the basic component of such a system is a switch (interconnection network) that has a capacity of interconnecting a large number of inputs to outputs. in this paper we present an analysis of an n1 x n2 asynchronous crossbar switch model for all-optical circuit-switching networks that incorporates multi-rate arrival traffic with varied arrival distributions. we compare the model behavior using traffic loads derived from the binomial, pascal, and poisson statistical distributions. we give efficient algorithms to compute the performance measures. we analyze the effect of load changes from particular traffic distribution streams on system performance and give a simple "economic" interpretation.  paul stirpe eugene pinsky
a single-relation module for a data base machine  the purpose of this paper is twofold. first, a set of design goals for data base machines is defined, together with a partial order of importance. the main objective is chosen to be a machine capable of executing any relational operation in constant time. second, architecture of a data base machine is described. associative array processors are employed together with other means to achieve very high performance. the difficulties arising from the proposed design are considered, various alternatives and trade-offs are discussed, and the effects of future technology are predicted.  bruce w. arden ran ginosar
efficient demultiplexing of incoming tcp packets  when a transport protocol segment arrives at a receiving system, the receiving system must determine which application is to receive the protocol segment. this decision is typically made by looking up a protocol control block (pcb) for the segment, based on information in the segment's header. pcb lookup (a form of demultiplexing) is typically one of the more expensive operations in handling inbound protocol segment [fe190].  many recent protocol optimizations for the transmission control protocol (tcp) [jac88] assume that a large component of tcp traffic is bulk-data transfers, which result in packet trains [jr86]. if packet trains are prevalent, there is a high likelihood that the next tcp segment is en route to the same application (i.e. uses the same pcb) as the previous tcp segment. in these environments a very simple one-pcb cache like those used in bsd systems yields very high cache hit rates.  however, there are classes of applications that do not form packet trains, and these applications do not perform well with a one- pcb cache. examples of such applications are quite common in the area of heads-down data entry into on- line transaction-processing (oltp) systems. oltp systems make heavy use of computer communications networks and have large aggregate-packet-rates but are also characterized by large numbers of connections, low per-connection packet rates, and rather small packets. this combination of characteristics results in a very low incidence of packet trains.  this paper uses a simple analytic approach to examine how different pcb lookup schemes perform with oltp traffic. one scheme is shown to work an order of magnitude better for oltp traffic than the one- pcb cache approach while still maintaining good performance for packet-train traffic.  paul e. mckenney ken f. dove
on the performance of tdd-td/cdma architectures with heterogeneous traffic this paper determines the capacity of a tdd- td/cdma architecturewhich supports different classes of subscribers and adopts aninterference-driven admission control policy. the blocking and theoutage probability of the system users are evaluated under varioustraffic conditions for several uplink/downlink configurations ofthe time slots, demonstrating that the time division full duplexapproach needs a careful tuning in order to maximize systemcapacity. our work further shows that even when data traffic playsthe predominant role, the tdd system can satisfyingly cope withremarkable traffic loads and support several erlangs of traffic percell. maurizio casoni maria luisa merani
phantom: a simple and effective flow control scheme this paper presents _phantom_, a simple constant space algorithm for rate based flow control. as shown by our simulations, it converges fast to a fair rate allocation while generating a moderate queue length. while our approach can be easily implemented in atm switches for managing abr traffic, it is also suitable for flow control in tcp router based networks. both the introduced overhead and the required modifications in tcp flow control systems are minimal. the implementation of this approach in tcp guarantees fairness and provides a unifying interconnection between tcp routers and atm networks. the new algorithm easily inter-operates with current tcp flow control mechanisms and thus can be gradually introduced into installed based tcp networks. yehuda afek yishay mansour zvi ostfeld
the sigma network  the sigma network is one of the most important element of the sigma system which is designed to improve productivity of a software.  the sigma network has been developed in order to establish a infrastructure which acts as development environment provided by logically integrated sigma workstations spread over various companies and inside the companies which approve the concept of the sigma system. it is also included in the scope of its development to enrich application programs mainly for message communication required by network community.  the network supports ieee802.3, digital packet exchange (x.25) and serial line under the tcp/ip layer and realizes end-to-end immediate communication.  sigma network is a name oriented virtual network defined by hierarchical name space (domain) and named objects placed under the domains. its key feature lies in the network management mechanism, i.e. name server.  k. saito
globally constrained power control across mulitple channels in wireless data networks  we investigate multi-channel transmission schemes for packetized wireless data networks. the transmitting unit transmits concurrently in several orthogonal channels (for example, distinct fdma bands or cdma codes) with randomly fluctuating interference and there is a global constraint on the total power transmitted across all channels at any time slot. incoming packets to the transfer are queued up in separate buffers, depending on the channel they are to be transmitted in. in each time slot, one packet can be transmitted in each channel from its corresponding queue. the issue is how much power to transmit in each channel, given the interference in it and the packet backlog, so as to optimize various power and delay costs associated with the system. we formulate the general problem taking a dynamic programming approach. through structural decomposition of the problem, we design practical novel algorithms for allocating power to various channels under the global constraint.  nicholas bambos sunil kandukuri
using pathchar to estimate internet link characteristics we evaluate **pathchar**, a tool that infers the characteristics of links along an internet path (latency, bandwidth, queue delays). looking at two example paths, we identify circumstances where **pathchar** is likely to succeed, and develop techniques to improve the accuracy of **pathchar**'s estimates and reduce the time it takes to generate them. the most successful of these techniques is a form of adaptive data collection that reduces the number of measurements **pathchar** needs by more than 90% for some links. allen b. downey
communications networks for the force xxi digitized battlefield  in striving to meet the increasing demands for timely delivery of multimedia information to the warfighter of the 21st century, the us army is undergoing a gradual evolution from its "legacy" communications networks to a flexible internetwork architecture based solidly on the underlying communications protocols and technology of the commercial internet. the framework for this new digitized battlefield, as described in the dod's joint technical architecture (jta), is taken from the civilian telecommunications infrastructure which, in many cases, differs appreciably from the rigors of the battlefield environment. the purpose of this paper is to survey the components and characteristics of the army's legacy communications networks, to illustrate the directions currently being taken for accomplishing this digitization, to describe the areas in which the civilian and military systems differ, and to define a glide path for convergence of the two technologies in support of the military's increasing appetite for information.  paul sass
dependency sequences and hierarchical clocks: efficient alternatives to vector clocks for mobile computing systems  vector clocks have been used to capture causal dependencies between processes in distributed computing systems. vector clocks are not suitable for mobile computing systems due to (i) lack of scalability: its size is equal to the number of nodes, and (ii) its inability to cope with fluctuations in the number of nodes. this paper presents two efficient alternatives to vector clock, namely, sets of dependency sequences, and hierarchical clock. both the alternatives are scalable and are immune to fluctuations in the number of nodes in the system.  ravi prakash mukesh singhal
a case for network musical performance  a network musical performance (nmp) occurs when a group of musicians, located at different physical locations, interact over a network to perform as they would if located in the same room. in this paper, we present a case for nmp as a practical internet application, and describe a method to ameliorate the effect of late and lost packets on nmp. we describe an nmp system that embodies this concept, that combines several existing standards (midi, mpeg 4 structured audio, rtp/avp, and sip) with a new rtp packetization for midi performance. we analyze nmp experiments performed on calren2 hosts on the uc berkeley, stanford, and caltech campuses.  john lazzaro john wawrzynek
the locus distributed operating system  locus is a distributed operating system which supports transparent access to data through a network wide filesystem, permits automatic replication of storage, supports transparent distributed process execution, supplies a number of high reliability functions such as nested transactions, and is upward compatible with unix. partitioned operation of subnet's and their dynamic merge is also supported.  the system has been operational for about two years at ucla and extensive experience in its use has been obtained. the complete system architecture is outlined in this paper, and that experience is summarized.  bruce walker gerald popek robert english charles kline greg thiel
adaptive rate control and qos provisioning in direct broadcast satellite networks adaptive rate control, if properly employed, is an effective mechanism to sustain acceptable levels of quality of service (qos) in wireless networks where channel and traffic conditions vary over time. in this paper we present an adaptive rate (source and channel) control mechanism, developed as part of an adaptive resource allocation and management (aram) algorithm, for use in direct broadcast satellite (dbs) networks. the algorithm performs admission control and dynamically adjusts traffic source rate and forward error correction (fec) rate in a co-ordinated fashion to satisfy qos requirements. to analyze its performance, we have simulated the adaptive algorithm with varying traffic flows and channel conditions. the traffic flow is based on a variable bit rate (vbr) source model that represents motion picture expert group (mpeg) traffic fluctuations while the dbs channel model is based on a two-state additive white gaussian noise (awgn) channel. for measures of performance, the simulator quantifies throughput, frame loss due to congestion during transmission as well as qos variations due to channel (fec) and source (mpeg compression and data transmission) rate changes. to show the advantage of the adaptive fec mechanism, we also present the performance results when fixed fec rates are employed. the results indicate significant throughput and/or quality gains are possible when the fec/source pairs are adjusted properly in co-ordination with source rate changes. fatih alagöz david walters amina alrustamani branimir vojcic raymond pickholtz
aitpm: a strategy for integrating ip with atm this paper describes research on new methods and architectures that enable the synergistic combination of ip and atm technologies. we have designed a highly scalable gigabit ip router based on an atm core and a set of tightly coupled general-purpose processors. this aitpm (pronounced "ip on atm" or, if you prefer, "ip-attem") architecture provides flexibility in congestion control, routing, resource management, and packet scheduling.the aitpm architecture is designed to allow experimentation with, and fine tuning of, the protocols and algorithms that are expected to form the core of the next generation ip in the context of a gigabit environment. the underlying multi-cpu embedded system will ensure that there are enough cpu and memory cycles to perform all ip packet processing at gigabit rates. we believe that the aitpm architecture will not only lead to a scalable high-performance gigabit ip router technology, but will also demonstrate that ip and atm technologies can be mutually supportive. guru parulkar douglas c. schmidt jonathan s. turner
delay analysis of a window tree conflict resolution algorithm in a local area network environment  expressions are found for the throughput and delay performance of a tree conflict resolution algorithm that is used in a local area network with carrier sensing (and possibly also collision detection). we assume that massey's constant size window algorithm is used to control access to the channel, and that the resulting conflicts (if any) are resolved using a capetanakis-like preorder traversal tree algorithm with d-ary splitting. we develop and solve functional equations for various performance metrics of the system and apply the "moving server" technique to calculate the main component of the delay. our results compare very favorably with those for csma protocols, which are commonly used in local area networks that support sensing.  george c. polyzos mart l. molle
a dynamic network architecture  network software is a critical component of any distributed system. because of its complexity, network software is commonly layered into a hierarchy of protocols, or more generally, into a protocol graph. typical protocol graphs--- including those standardized in the iso and tcp/ip network architectures--- share three important properties; the protocol graph is simple, the nodes of the graph (protocols) encapsulate complex functionality, and the topology of the graph is relatively static. this paper describes a new way to organize network software that differs from conventional architectures in all three of these properties. in our approach, the protocol graph is complex, individual protocols encapsulate a single function, and the topology of the graph is dynamic. the main contribution of this paper is to describe the ideas behind our new architecture, illustrate the advantages of using the architecture, and demonstrate that the architecture results in efficient network software.  sean w. o'malley larry l. peterson