waashk/acm huggingface dataset:
the hcn: a versatile interconnection network based on cubes  this paper introduces a family of interconnection networks for loosely-coupled multiprocessors called hierarchical cubic networks (hcns). hcns use the well- known hypercube network as their basic building block. using a considerably lower number of links per node, hcns realize lower network diameters than the hypercube. the performance of several well-known applications on a hypothetical system employing the hcn is identical to their performance on a hypercube. hcns thus enjoy the same advantages as a hypercube, albeit with considerably simpler interconnections.  k. ghose k. r. desai
an analysis of wide-area name server traffic: a study of the internet domain name system  over a million computers implement the internet's domain name system of dns, making it the world's most distributed database and the internet's most significant source of wide-area rpc-like traffic. last year, over eight percent of the packets and four percent of the bytes that traversed the nsfnet were due to dns. we estimate that a third of this wide-area dns traffic was destined to seven root name servers. this paper explores the performance of dns based on two 24-hour traces of traffic destined to one of these root name servers. it considers the effectiveness of name caching and retransmission timeout calculation, shows how algorithms to increase dns's resiliency lead to disastrous behavior when servers fail or when certain implementation faults are triggered, explains the paradoxically high fraction of wide-area dns packets, and evaluates the impact of flaws in various implementations of dns. it shows that negative caching would improve dns performance only marginally in an internet of correctly implemented name servers. it concludes by calling for a fundamental change in the way we specify and implement future name servers and distributed applications.  peter b. danzig katia obraczka anant kumar
building blocks for data flow prototypes  a variety of proposed architectures for data flow computers have been advanced. evaluation of the practical potential of these proposals is being studied through analysis and simulation, but these techniques cannot be used to study a machine design in sufficient detail to make accurate predictions of performance. as a basis for extrapolating cost/performance of these architectures, and for developing a methodology for data flow program preparation, the construction of prototype machines is needed. in this paper we present our plan for realizing experimental data flow machines as packet communication systems using two types of hardware elements: a microprogrammed processing element with provision for packet transmission and reception; and a router unit used to build networks to support packet communication among processing elements.  jack b. dennis g. andrew boughton clement k.c. leung
an evaluation of quality of service characteristics of pacs packet channel  a novel application on the recently emerging wireless personal communications systems (pcs) is the multimedia communication. in this paper, we evaluate multimedia communications capability and quality of service characteristics of one of the pcs standards, personal access communications systems's (pacs) packet channel (ppc) using simulation modeling. the performance of ppc's slot aggregation and data-sense multiple access techniques are studied by considering the downlink and uplink in a single cell and combined uplink/downlink in two cells and changing various parameters such as the number of users and certain protocol parameters. interconnection of ppc with the internet is discussed next. frame rates of mpeg-1 coded images transmitted in a pacs cell as ip datagrams are determined. handover characteristics of ppc downlink are studied by changing different parameters such as the cell size, the speed of the mobile host and time between handovers. the results clearly establish that multimedia communication on ppc is only feasible at lower bandwidths and frame rates and only a few users per cell can be supported. careful tuning of ppc protocol parameters is required. there is one parameter whose variation gives opposite results on the downlink and uplink.  behcet sarikaya mehmet ulema
self-similarity through high-variability: statistical analysis of ethernet lan traffic at the source level a number of recent empirical studies of traffic measurements from a variety of working packet networks have convincingly demonstrated that actual network traffic is _self-similar_ or _long-range dependent_ in nature (i.e., bursty over a wide range of time scales) - in sharp contrast to commonly made traffic modeling assumptions. in this paper, we provide a plausible physical explanation for the occurrence of self- similarity in high-speed network traffic. our explanation is based on convergence results for processes that exhibit _high variability_ (i.e., infinite variance) and is supported by detailed statistical analyses of real- time traffic measurements from ethernet lan's at the level of individual sources.our key mathematical result states that the superposition of many on/off sources (also known as _packet trains_) whose on-periods and off- periods exhibit the _noah effect_ (i.e., have high variability or infinite variance) produces aggregate network traffic that features the _joseph effect_ (i.e., is self-similar or long-range dependent). there is, moreover, a simple relation between the parameters describing the intensities of the noah effect (high variability) and the joseph effect (self-similarity). an extensive statistical analysis of two sets of high time-resolution traffic measurements from two ethernet lan's (involving a few hundred active source- destination pairs) confirms that the data at the level of individual sources or source- destination pairs are consistent with the noah effect. we also discuss implications of this simple physical explanation for the presence of self- similar traffic patterns in modern high-speed network traffic for (i) parsimonious traffic modeling (ii) efficient synthetic generation of realistic traffic patterns, and (iii) relevant network performance and protocol analysis. walter willinger murad s. taqqu robert sherman daniel v. wilson
identification in computer networks  to communicate across a network system, entities within the system need to be able to identify one another. an identifier usually takes the form of a name or an address. conventions for the assignment of these identifiers and their resolution affect many aspects of network design. identification is thus a crucial issue for network architecture and standardization. in this paper, our discussion is first devoted to the semantics of names, addresses, and routes, with emphasis on the relationships among them. we then examine the implications of layered network architecture, syntactic differences of identifiers, and broadcast communication. finally, we turn our attention to naming and addressing in large dynamic networks.  zaw-sing su
low-loss tcp/ip header compression for wireless networks  wireless is becoming a popular way to connect mobile computers to the internet and other networks. the bandwidth of wireless links will probably always be limited due to properties of the physical medium and regulatory limits on the use of frequencies for radio communication. therefore, it is necessary for network protocols to utilize the available bandwidth efficiently. headers of ip packets are growing and the bandwidth required for transmitting headers is increasing. with the coming of ipv6 the address size increases from 4 to 16 bytes and the basic ip header increases from 20 to 40 bytes. moreover, most mobility schemes tunnel packets addressed to mobile hosts by adding an extra ip header or extra routing information, typically increasing the size of tcp/ipv4 headers to 60 bytes and tcp/ipv6 headers to 100 bytes. in this paper, we provide new header compression schemes for udp/ip and tcp/ip protocols. we show how to reduce the size of udp/ip headers by an order of magnitude, down to four to five bytes. our method works over simplex links, lossy links, multi-access links, and supports multicast communication. we also show how to generalize the most commonly used method for header compression for tcp/ipv4, developed by jacobson, to ipv6 and multiple ip headers. the resulting scheme unfortunately reduces tcp throughput over lossy links due to unfavorable interaction with tcp's congestion control mechanisms. however, by adding two simple mechanisms the potential gain from header compression can be realized over lossy wireless networks as well as point-to-point modem links.  mikael degermark mathias engan björn nordgren stephen pink
on the performance of slotted aloha in a spread spectrum environment  we present an extension of the slotted aloha protocol for use in a spread spectrum packet radio environment. with spread spectrum, we assume that n distinct codes are available, and that each code can be treated as a separate channel. running an independent copy of the protocol on each of these channels would be undesirable, since each user would have to select one channel to monitor for packets addressed to it, inducing a logical partitioning of the user population into n groups. to preserve the logical connectivity of the network, we examine the effect of separating packet transmissions into two parts, a short preamble, which is sent over a public channel, and followed by the body,> which is sent over a private channel. we assume that m of the available codes are used as preamble channels, and the remaining n - m codes are used for actual packet transmissions. if m (@@@@) n, then the network can support broadcast and multicast packets, and still make use of all of the available channels.  panos economopoulos mart l. molle
a satellite-augmented cellular network concept  some next-generation personal communication systems propose the use of satellite systems for extending geographical coverage of cellular service. we pursue the idea of using satellite capacity to offload congestion within the area serviced by the terrestrial network. an integrated satellite-cellular network configuration is considered. the performance of this system is evaluated by means of an analytical model for a one-dimensional (highway) cellular system overlaid with satellite footprints and by means of simulation for a planar cellular network with satellite spot beam support. under certain re-use assumptions, an improvement is found in the blocking performance of the integrated system over the erlang-b blocking of a purely cellular circuit switched systems. this is achieved by efficient partitioning (static) of the total bandwidth into space and terrestrial segments. major factors that influence performance, such as different reuse considerations on the satellite and cellular systems, cell size to footprint size ratios, admission control and call management policies, and changes in traffic patterns, are also investigated.  deepak ayyagari anthony ephremides
performance of sna's lu-lu session protocols  sna is both an architecture and a set of products built in conformance with the architecture (1,2,3). the architecture is layered and precisely defined; it is both evolutionary and cost effective for implementing products. perhaps the largest component of cost effectiveness is performance: transaction throughput and response times. for sna, this involves data link control protocols (for sdlc and s/370 channel dlc's), routing algorithms, protocols used on the sessions that connect logical units (lu-lu session protocols), and interactions among them.  sna's dlc and routing protocols have been discussed elsewhere (4,5,6); this talk examines protocols on sessions between logical units (lu-lu session protocols) and illustrates the results of design choices by comparing the performance of various configurations.  james p. gray
two issues in reservation establishment this paper addresses two issues related to resource reservation establishment in packet switched networks offering real-time services. the first issue arises out of the natural tension between the local nature of reservations (i.e., they control the service provided on a particular link) and the end-to-end nature of application service requirements. how do reservation establishment protocols enable applications to receive their desired end-to-end service? we review the current one-pass and two-pass approaches, and then propose a new hybrid approach called one-pass-with-advertising. the second issue in reservation establishment we consider arises from the inevitable heterogeneity in network router capabilities. some routers and subnets in the internet will support real-time services and others, such as ethernets, will not. how can a reservation establishment mechanism enable applications to achieve the end-to- end service they desire in the face of this heterogeneity? we propose an approach involving replacement services and advertising to build end-to-end service out of heterogeneous per-link service offerings. scott shenker lee breslau
observing tcp dynamics in real networks  the behavior of the tcp protocol in simple situations is well-understood, but when multiple connections share a set of network resources the protocol can exhibit surprising phenomena. earlier studies have identified several such phenomena, and have analyzed them using simulation or observation of contrived situations. this paper shows how, by analyzing traces of a busy segment of the internet, it is possible to observe these pheonomena in "real life" and measure both their frequency and their effects on performance. a tcp implementation might use similar techniques to support rate-based congestion control.  jeffrey c. mogul
virtualclock: a new traffic control algorithm for packet-switched networks  one of the challenging research issues in building high-speed packet- switched networks is how to control the transmission rate of statistical data flows. this paper describes a new traffic control algorithm, virtualclock, for high- speed network applications. virtualclock monitors the average transmission rate of statistical data flows and provides every flow with guaranteed throughput and low queueing delay. it provides firewall protection among individual flows, as in a tdm system, while retaining the statistical multiplexing advantages of packet switching. simulation results show that the virtualclock algorithm meets all its design goals.  lixia zhang
adaptive error coding using channel prediction  in this paper, we construct a finite-state markov chain model for a rayleigh fading channel by partitioning the range of the received signal envelope into k intervals. using a simulation of the classic two-ray rayleigh fading model, a markov transition probability matrix is obtained. using this matrix to predict the channel state, we introduce an adaptive forward error correction (fec) coding scheme. simulation results are presented to show that the adaptive fec coding scheme significantly improves the performance of a wireless communication system.  r. chen k. c. chua b. t. tan c. s. ng
tcp extensions for space communications  the space communication environment and mobile and wireless communication environments show many similarities when observed from the perspective of a transport protocol. both types of environments exhibit loss caused by data corruption and link outage, in addition to congestion-related loss. the constraints imposed by the two environments are also similar---power, weight, and physical volume of equipment are scarce resources. finally, it is not uncommon for communication channel data rates to be severely limited and highly asymmetric. we are working on solutions to these types of problems for space communication environments, and we believe that these solutions may be applicable to the mobile and wireless community. as part of our work, we have defined and implemented the space communications protocol standards-transport protocol (scps-tp), a set of extensions to tcp that address the problems that we have identified. the results of our performance tests, both in the laboratory and on actual satellites, indicate that the scps-tp extensions yield significant improvements in throughput over unmodified tcp on error- prone links. additionally, the scps modifications significantly improve performance over links with highly asymmetric data rates.  robert c. durst gregory j. miller eric j. travis
rethinking the tcp nagle algorithm  modern tcp implementations include a mechanism, known as the nagle algorithm, which prevents the unnecessary transmission of a large number of small packets. this algorithm has proved useful in protecting the internet against excessive packet loads. however, many applications suffer performance problems as a result of the traditional implementation of the nagle algorithm. an interaction between the nagle algorithm and tcp's delayed acknowledgement policy can create an especially severe problems, through a temporary "deadlock." these flaws in the nagle algorithm have prompted many application implementors to disable it, even in cases where this is neither necessary nor wise.  we categorize the applications that should and should not disable the nagle algorithm, and we show that for some applications that often disable the nagle algorithm, equivalent performance can be obtained through an improved implementation of the algorithm. we describe five possible modifications, including one novel proposal, and analyze their performance on benchmark tests. we also describe a receiver-side modification that can help in some circumstances.  j. c. mogul g. minshall
on network-aware clustering of web clients  being able to identify the groups of clients that are responsible for a significant portion of a web site's requests can be helpful to both the web site and the clients. in a web application, it is beneficial to move content closer to groups of clients that are responsible for large subsets of requests to an origin server. we introduce clusters\\---a grouping of clients that are close together topologically and likely to be under common administrative control. we identify clusters using a ``network-aware" method, based on information available from bgp routing table snapshots.  balachander krishnamurthy jia wang
draft (abstract only): dynamically reconfigurable architecture for factoring tests  the draft architecture is a 256 bit system design for extended precision integer arithmetic. it is intended primarily for high speed factoring of large integers. major architectural features include a segmentable rdo which allows parallel computations in up to eight independent all segments. each segment operates from a local control store with a common micro-instruction address broadcast to all segments by a single sequencer. execution of the current operation by the segment is conditional on the operation selected and the status of a local condition code. a micro-program development environment including micro-assembler and simulator has been implemented. a prototype draft machine is currently under construction.  donald m. chiarulli walter g. rudd ducan a. buell
a comparison of dynamic branch predictors that use two levels of branch history  recent attention to speculative execution as a mechanism for increasing performance of single instruction streams has demanded substantially better branch prediction than what has been previously available. we [1,2] and pan, so, and rahmen [4] have both proposed variations of the same aggressive dynamic branch predictor for handling those needs. we call the basic model two-level adaptive branch prediction; pan, so, and rahmeh call it correlation branch prediction. in this paper, we adopt the terminology of [2] and show that there are really nine variations of the same basic model. we compare the nine variations with respect to the amount of history information kept. we study the effects of different branch history lengths and pattern history table configurations. finally, we evaluate the cost effectiveness of the nine variations.  tse-yu yeh yale n. patt
the expandable split window paradigm for exploiting fine-grain parallelsim  we propose a new processing paradigm, called the expandable split window (esw) paradigm, for exploiting fine-grain parallelism. this paradigm considers a window of instructions (possibly having dependencies) as a single unit, and exploits fine-grain parallelism by overlapping the execution of multiple windows. the basic idea is to connect multiple sequential processors, in a decoupled and decentralized manner, to achieve overall multiple issue. this processing paradigm shares a number of properties of the restricted dataflow machines, but was derived from the sequential von neumann architecture. we also present an implementation of the expandable split window execution model, and preliminary performance results.  manoj franklin gurindar s. sohi
a contention/reservation access protocol for speech and data integration in tdma-based advanced mobile systems  the performance of third generation mobile systems is greatly influenced by the multiple access protocols used in the radio access system. the paper introduces a multiple access protocol, sir (service integration for radio access), which has the potential for accommodating the requirements of speech and bursty data traffic in an efficient way. sir is evolved from an access protocol (prma++) studied within the framework of the tdma-based version of the european evolving standard for third generation mobile systems. in particular, sir uses the same frame structure and in-band signalling but introduces a contention-free handling of data bandwidth requests while meeting speech service requirements via basic prma++ mechanisms.  giuseppe anastasi davide grillo luciano lenzini enzo mingozzi
packet routing algorithms for integrated switching networks  repeated studies have shown that a single switching technique, either circuit or packet switching, cannot optimally support a heterogeneous traffic mix composed of voice, video and data. integrated networks support such heterogeneous traffic by combining circuit and packet switching in a single network. to manage the statistical variations of network traffic, we introduce a new, adaptive routing algorithm called hybrid, weighted routing. simulations show that hybrid, weighted routing is preferable to other adaptive routing techniques for both packet switched networks and integrated networks.  daniel a. reed chong-kwon kim
performance evaluation of the powerpc 620 microarchitecture the powerpc 620 microprocessor is the most recent and performance leading member of the powerpc family. the 64-bit powerpc 620 microprocessor employs a two-phase branch prediction scheme, dynamic renaming for all the register files, distributed multi-entry reservation stations, true out-of-order execution by six execution units, and a completion buffer for ensuring precise exceptions. this paper presents an instruction-level performance evaluation of the 620 microarchitecture. a performance simulator is developed using the vmw (visualization-based microarchitecture workbench) retargetable framework. the vmw-based simulator accurately models the microarchitecture down to the machine cycle level. extensive trace-driven simulation is performed using the spec92 benchmarks. detailed quantitative analyses of the effectiveness of all key microarchitecture features are presented. trung a. diep christopher nelson john paul shen