waashk/acm huggingface dataset:
security issues with tcp/ip an introduction to network security , basic definitions and aa brief discussion of the architecture of tcp/ip as well as the open system intercornnection(osi) reference model open the paper. the relationship between tcp/ip and of some osi layers is described. an indepth look is provided to the major protocols in tcp/ip suite and the security features and problems in this suite of protocols. the secutiy problems are discussed in the context ofthe protocol services. renqi li e. a. unger
cpu sim 3.1: a tool for simulating computer architectures for computer organization classes cpu sim 3.1 is an educational software package written in java foruse in cs3 courses. cpu sim provides students an active learningenvironment in which they can design, modify, and compare variouscomputer architectures at the register-transfer level and higher.they can run assembly language or machine language programs forthose architectures through simulation. cpu sim is a completedevelopment environment, including dialog boxes for designing thecpu architecture, a text editor for editing assembly languageprograms, an assembler, several display windows for viewing theregisters and rams during the execution of programs, and manydebugging features such as the ability to step forward or backwardduring execution, inspecting and optionally changing the values inthe registers and rams after each step. these features andsuggested uses of cpu sim in cs3 classes are discussed. dale skrien
benchmarking a vector-processor prototype based on multithreaded streaming/fifo vector (msfv) architecture  this paper presents the benchmark results on a vector-processor prototype based on the msfv (multithreaded streaming/fifo vector) architecture. the msfv architecture is single-chip oriented, and thus its main object is to save the off-chip memory bandwidth by exploiting the register bandwidth instead. the register bandwidth is exploited by the synergism of fifo register, chaining, streaming, and multithreading. this paper tries to identify the strength and weakness of those architectural features. the results for basic vector operations and livermore fortran kernels are reported in terms of normalized flopc (floating-point operations per clock cycle) and compared to previously- reported results on the cray x-mp, y-mp, fujitsu vp-200, hitachi s-810/20, nec sx-2, and sx-3. these comparisons show that, for many basic vector operations, the execution rate of the msfv prototype results in worst due to its saving thememory bandwidth. however, for livermore fortran kernels, the msfv prototype results in worst due to its saving the memory bandwidth. however, for livermore fortran kernels, the msfv prototype outperforms the vp-200 by 2.11 times (geometric mean) and one processor of the x-mp by 1.22 times (geometric mean) in terms of flopc. also, it is 0.67 times (geometric mean) faster than the s-810/20, and 0.76 times (geometric mean) faster than the sx-2. the paper concludes that the msfv architecture is successful in saving the memory bandwidth.  tetsuo hironaka takashi hashimoto keizo okazaki kazuaki murakami shinji tomita
hardware support for fast capability-based addressing  traditional methods of providing protection in memory systems do so at the cost of increased context switch time and/or increased storage to record access permissions for processes. with the advent of computers that supported cycle- by-cycle multithreading, protection schemes that increase the time to perform a context switch are unacceptable, but protecting unrelated processes from each other is still necessary if such machines are to be used in non- trusting environments.  this paper examines guarded pointers, a hardware technique which uses tagged 64-bit pointer objects to implement capability-based addressing. guarded pointers encode a segment descriptor into the upper bits of every pointer, eliminating the indirection and related performance penalties associated with traditional implementations of capabilities. all processes share a single 54-bit virtual address space, and access is limited to the data that can be referenced through the pointers that a process has been issued. only one level of address translation is required to perform a memory reference. sharing data between processes is efficient, and protection states are defined to allow fast protected subsystem calls and create unforgeable data keys.  nicholas p. carter stephen w. keckler william j. dally
a survey of energy efficient network protocols for wireless networks wireless networking has witnessed an explosion of interest from consumers in recent years for its applications in mobile and personal communications. as wireless networks become an integral component of the modern communication infrastructure, energy efficiency will be an important design consideration due to the limited battery life of mobile terminals. power conservation techniques are commonly used in the hardware design of such systems. since the network interface is a significant consumer of power, considerable research has been devoted to low-power design of the entire network protocol stack of wireless networks in an effort to enhance energy efficiency. this paper presents a comprehensive summary of recent work addressing energy efficient and low-power design within all layers of the wireless network protocol stack. christine e. jones krishna m. sivalingam prathima agrawal jyh cheng chen
modeling rpc performance  distributed computing applications are collections of processes allocated across a network that cooperate to accomplish common goals. the applications require the support of a distributed computing runtime environment that provides services to help manage process concurrency and interprocess communication. this support helps to hide much of the inherent complexity of distributed environments via industry standard interfaces and permits developers to create more portable applications. the resource requirements of the runtime services can be significant and may impact application performance and system throughput. this paper describes work done to study the potential benefits of redesigning some aspects of the dce rpc and its current implementation on a specific platform.  j. a. rolia m. starkey g. boersma
approximate mean value analysis algorithms for queuing networks: existence, uniqueness, and convergence results  this paper is concerned with the properties of nonlinear equations associated with the scheweitzer-bard (s-b) approximate mean value analysis (mva) heuristic for closed product-form queuing networks. three forms of nonlinear s-b approximate mva equations in multiclass networks are distinguished: schweitzer, minimal, and the nearly decoupled forms. the approximate mva equations have enabled us to: (a) derive bounds on the approximate throughput; (b) prove the existence and uniqueness of the s-b throughput solution, and the convergence of the s-b approximation algorithm for a wide class of monotonic, single-class networks; (c) establish the existence of the s-b solution for multiclass, monotonic networks; and (d) prove the asymptotic (i.e., as the number of customers of each class tends to ∞) uniqueness of the s-b throughput solution, and (e) the convergence of the gradient projection and the primal- dual algorithms to solve the asymptotic versions of the minimal, the schweitzer, and the nearly decoupled forms of mva equations for multiclass networks with single server and infinite server nodes. the convergence is established by showing that the approximate mva equations are the gradient vector of a convex function, and by using results from convex programming and the convex duality theory.  k. r. pattipati m. m. kostreva j. l. teele
decentralised approaches for network management centralised network management has shown inadequacy for efficient management of large heterogenous networks. as a result, several distributed approaches have been adapted to overcome the problem. this paper is a review of decentralised network management techniques and technologies. we explain distributed architectures for network management, and discuss some of the most important implemented distributed network management systems. a comparison is made between these approaches to show the pitfalls and merits of each. mohsen kahani h. w. peter beadle
on computing per-session performance bounds in high-speed multi-hop computer networks  we present a technique for computing upper bounds on the distribution of individual per-session performance measures such as delay and buffer occupancy for networks in which sessions may be routed over several "hops." our approach is based on first stochastically bounding the distribution of the number of packets (or cells) which can be generated by each traffic source over various lengths of time and then "pushing" these bounds (which are then shown to hold over new time interval lengths at various network queues) through the network on a per-session basis. session performance bounds can then be computed once the stochastic bounds on the arrival process have been characterized for each session at all network nodes. a numerical example is presented and the resulting distributional bounds compared with simulation as well as with a point-valued worst-case performance bound.  jim kurose
high performance visualization of time-varying volume data over a wide-area network status  this paper presents an end-to-end, low-cost solution for visualizing time- varying volume data rendered on a parallel computer located at a remote site. pipelining and careful grouping of processors are used to hide i/o time and to maximize processor utilization. compression is used to significantly cut down the cost of transferring output images from the parallel computer to a display device through a wide-area network. this complete rendering pipeline makes possible highly efficient rendering andremote viewing of high-resolution time- varying data sets in the absence of high-speed network and parallel i/o support. to study the performance of this rendering pipeline and to demonstrate high-performance remote visualization, tests were conducted on a pc cluster in japan as well as an sgi origin 2000 operated at the nasa ames research center with the display located at uc davis.  kwan-liu ma david m. camp
modeling a transport layer protocol using first-order logic  we use a hybrid model based on the first-order logic to specify and verify a transport layer protocol. in this model we specify a protocol as a set of state machines. time expressions are used to describe the temporal relations of transitions. given the specification of a protocol, we verify its properties by logical deduction. reasoning techniques such as decomposition and abstraction are used to reduce the verification complexity.  the transport protocol consists of an active process, a passive process, and two communication channels. each of these components is specified by this model. an outline of verification of this protocol is given.  h p lin
a simplified lan protocol for practicing file transfer, resource locating, and elementary distributed problem solving  local area networks exist for transferring files and messages and sharing resources, but do not address the areas of resource locating and elementary distributed problem solving. in order to better understand both the basics of blocked asynchronous protocols and distributed problem solving, an experimental protocol has been created which allows a collection of microcomputers not only to transfer files in an error free environment but to also conduct resource locating and elementary distributed problem solving. the students may then apply hands on experience to the understanding of current blocked asynchronous protocols and eventually leading into the newly created ieee 802 standards.  curt m. white
a scalable, robust network for parallel computing  cx, a network-based computational exchange, is presented. the system's design integrates variations of ideas from other researchers, such as work stealing, non- blocking tasks, eager scheduling, and space-based coordination. the object- oriented api is simple, compact, and cleanly separates application logic from the logic that supports interprocess communication and fault tolerance. computations, of course, run to completion in the presence of computational hosts that join and leave the ongoing computation. such hosts, or producers, use task caching and prefetching to overlap computation with interprocessor communication. to break a potential task server bottleneck, a network of task servers is presented. even though task servers are envisioned as reliable, the self-organizing, scalable network of _n_ servers, described as a _sibling-connected fat tree_, tolerates a sequence of _n_ \\--- 1 server failures. tasks are distributed throughout the server network via a simple "diffusion" process.  cx is intended as a test bed for research on automated silent auctions, reputation services, authentication services, and bonding services. cx also provides a test bed for algorithm research into network-based parallel computation.  peter cappello dimitros mourloukos
a system architecture for the concurrent evaluation of applicative program expressions  the paper outlines the principles for the concurrent evaluation of applicative programs based on berklings reduction language. the recursive style of program design supported by this language lends itself to a recursive partitioning scheme which, for suitable program expressions, generates dynamically a hierarchy of processes for the concurrent evaluation of subexpressions. this hierarchy can elegantly be mapped onto a system of cooperating reduction machines featuring a stack architecture. a special ticket mechanism enforces an upper limit on the number of processes that, at any time, may exist within the system, which does not significantly exceed the number of the available machines.  claudia schmittgen werner kluge
object-oriented cosynthesis of distributed embedded systems  this article describes a new hardware-software cosynthesis algorithm that takes advantage of the structure inherent in an object-oriented specification. the algorithm creates a distributed system implementation with arbitrary topology, using the object-oriented structure to partition functionality in addition to scheduling and allocating processes. process partitioning is an especially important optimization for such systems because the specification will not, in general, take into account the process structure required for efficient execution on the distributed engine. the object-oriented specification naturally provides both coarse-grained and fine-grained partitions of the system. our algorithm uses that multilevel structure to guide synthesis. experimental results show that our algorithm takes advantage of the object- oriented specification to quickly converge on high-quality implementations.  wayne wolf
resource aggregation for fault tolerance in integrated services networks for several real-time applications it is critical that the failure of a network component does not lead to unexpected termination or long disruption of service. in this paper, we propose a scheme called raft (resource aggregation for fault tolerance) that guarantees recovery in a timely and resource- efficient manner. raft is presented in the framework of the reliable back-bone (rbone), a virtual network layered on top of an integrated services network. applications can request fault tolerance against rbone link and node failures. the basic idea of raft is to setup every fault tolerant flow along a secondary path that serves as a backup in case the primary path fails. the secondary path resource reservations are aggregated whenever possible to reduce the overhead of providing fault tolerance. we show that the rsvp resource reservation protocol can support raft with simple extensions. constantinos dovrolis parameswaran ramanathan
lower than best effort: a design and implementation  in recent years, the internet architecture has been augmented so that better- than-best-effort (bbf) services, in the form of reserved resources for specific flows, can be provided by the network. to date, this has been realized through two different and sequentially developed efforts. the first is known as integrated services and focuses on specific bounds on bandwidth and/or delay for specific flows. the differential service model was later introduced, which presented a more aggregated and local perspective regarding the forwarding of traffic. a direction that is missing in today's work on service models is a defined schema used to purposely degrade certain traffic to various levels below that of best effort. in a sense, a new direction that provides a balancing effect in the deployment of bbe service. this is particularly evident with continual and parallel short transaction flows (like that used for web applications) over low bandwidth links that are not subject to any backoff penalty incurred by congestion because state does not persist. in a more indirect perspective, our model correlates degraded service with the application of usage and security policies --- administrative decisions that can operate in tandem or disjointly from conditions of the network. this paper attempts to address these and other issues and presents the design and implementation of such a new degraded service model and queuing mechanism used to support it.  ken carlberg panos gevros jon crowcroft
signal design and system operation of globalstar versus is-95 cdma - similarities and differences  the globalstar^{tm} system provides telephone and data services to and from mobile and fixed users in the area between ± 70 degrees latitude. connection between user terminals and the pstn is established through fixed terrestrial gateways via a constellation of low earth orbiting leo satellites. globalstar uses an extension of the is - 95 cdma standard that is used in terrestrial digital cellular systems. the leo satellite link is sufficiently different from the terrestrial cellular link that certain departures from is - 95 were needed both in signal design as well as in system operation. this paper describes some of the similarities and differences of globalstar air interface versus is - 95.  leonard schiff a. chockalingam
effects of ad hoc layer medium access mechanisms under tcp  mobile computing is the way of the future, as evident by such initiatives as bluetooth, iceberg and homerf. however, for mobile computing to be successful, an obvious layer, the mac layer, must be efficient in channel access and reservation . therefore, in-dpeth understanding is needed of the wireless mac layerif wireless computing is to takeoff. many random access wireless mac protocols have been proposed and even standardized. however, there has yet been an attempt to understand why certain designs are used and what makes certain protocols better than others. in this paper, we survey several popular, contemporary, wireless, random access mac protocols and determine the effects behind the design choices of these protocols.  ken tang mario correa mario gerla
bayeux: an architecture for scalable and fault-tolerant wide-area data dissemination  the demand for streaming multimedia applications is growing at an incr edible rate. in this paper, we propose bayeux, an efficient application-level multicast system that scales to arbitrarily large receiver groups while tolerating failures in routers and network links. bayeux also includes specific mechanisms for load-balancing across replicate root nodes and more efficient bandwidth consumption. our simulation results indicate that bayeux maintains these properties while keeping transmission overhead low. to achieve these properties, bayeux leverages the architecture of tapestry, a fault- tolerant, wide-area overlay routing and location network.  shelley q. zhuang ben y. zhao anthony d. joseph randy h. katz john d. kubiatowicz
broadcast scheduling for information distribution  broadcast data delivery is encountered in many applications where there is a need to disseminate information to a large user community in a wireless asymmetric communication environment. in this paper, we consider the problem of scheduling the data broadcast such that average response time experienced by the users is low. in a push-based system, where the users cannot place requests directly to the server and the broadcast schedule should be determined based solely on the access probabilities, we formulate a deterministic dynamic optimization problem, the solution of which provides the optimal broadcast schedule. properties of the optimal solution are obtained and then we propose a suboptimal dynamic policy which achieves average response time close to the lower bound. the policy has low complexity, it is adaptive to changing access statistics, and is easily generalizable to multiple broadcast channels. in a pull-based system where the users may place requests about information items directly to the server, the scheduling can be based on the number of pending requests for each item. suboptimal policies with good performance are obtained in this case as well. finally, it is demonstrated by a numerical study that as the request generation rate increases, the achievable performance of the pull- and push-based systems becomes almost identical.  chi-jiun su leandros tassiulas vassilis j. tsotras
efficient algorithms for scheduling data broadcast  with the increasing acceptance of wireless technology, mechanisms to efficiently transmit information to wireless clients are of interest. the environment under consideration is asymmetric in that the information server has much more bandwidth available, as compared to the clients. it has been proposed that in such systems the server should broadcast the information periodically. a broadcast schedule determines what is broadcast by the server and when. this paper makes the simple, yet useful, observation that the problem of broadcast scheduling is related to the problem of fair queueing. based on this observation, we present a log-time algorithm for scheduling broadcast, derived from an existing fair queueing algorithm. this algorithm significantly improves the time-complexity over previously proposed broadcast scheduling algorithms. modification of this algorithm for transmissions that are subject to errors is considered. also, for environments where different users may be listening to different number of broadcast channels, we present an algorithm to coordinate broadcasts over different channels. simulation results are presented for proposed algorithms.  sohail hameed nitin h. vaidya