SIGMETRICS '04/Performance '04最新文献

{"title":"A model of BGP routing for network engineering","authors":"N. Feamster, Jared Winick, J. Rexford","doi":"10.1145/1005686.1005726","DOIUrl":"https://doi.org/10.1145/1005686.1005726","url":null,"abstract":"The performance of IP networks depends on a wide variety of dynamic conditions. Traffic shifts, equipment failures, planned maintenance, and topology changes in other parts of the Internet can all degrade performance. To maintain good performance, network operators must continually reconfigure the routing protocols. Operators configure BGP to control how traffic flows to neighboring Autonomous Systems (ASes), as well as how traffic traverses their networks. However, because BGP route selection is distributed, indirectly controlled by configurable policies, and influenced by complex interactions with intradomain routing protocols, operators cannot predict how a particular BGP configuration would behave in practice. To avoid inadvertently degrading network performance, operators need to evaluate the effects of configuration changes before deploying them on a live network. We propose an algorithm that computes the outcome of the BGP route selection process for each router in a single AS, given only a static snapshot of the network state, without simulating the complex details of BGP message passing. We describe a BGP emulator based on this algorithm; the emulator exploits the unique characteristics of routing data to reduce computational overhead. Using data from a large ISP, we show that the emulator correctly computes BGP routing decisions and has a running time that is acceptable for many tasks, such as traffic engineering and capacity planning.","PeriodicalId":172626,"journal":{"name":"SIGMETRICS '04/Performance '04","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122707308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Harpoon: a flow-level traffic generator for router and network tests","authors":"J. Sommers, Hyungsuk Kim, P. Barford","doi":"10.1145/1005686.1005733","DOIUrl":"https://doi.org/10.1145/1005686.1005733","url":null,"abstract":"We describe Harpoon, a new application-independent tool for generating representative packet traffic at the IP flow level. Harpoon is a configurable tool for creating TCP and UDP packet flows that have the same byte, packet, temporal, and spatial characteristics as measured at routers in live environments. We validate Harpoon using traces collected from a live router and then demonstrate its capabilities in a series of router performance benchmark tests.","PeriodicalId":172626,"journal":{"name":"SIGMETRICS '04/Performance '04","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128384432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A fast simulation framework for IEEE 802.11-operated wireless LANs","authors":"Hwangnam Kim, J. Hou","doi":"10.1145/1005686.1005706","DOIUrl":"https://doi.org/10.1145/1005686.1005706","url":null,"abstract":"In this paper, we develop a fast simulation framework for IEEE 802.11-operated wireless LANs (WLANs), in which a large number of packets are abstracted as a single fluid chunk, and their behaviors are approximated with analytic fluid models and figured into the simulation. We first derive the analytical model that characterizes data transmission activities in IEEE 802.11-operated WLANs with/without the RTS/CTS mechanism. All the control overhead incurred in the physical and MAC layers, as well as system parameters specified in IEEE 802.11 [12] are faithfully figured in. We validate the model with simulation in cases in which the network is and is not saturated. We then implement, with the use of the time stepping technique [21], the fast simulation framework for WLANs in ns-2 [2], and conduct a comprehensive simulation study to evaluate the framework in terms of speed-up and errors incurred under a variety of network configurations.The simulation results indicate that the proposed framework is indeed effective in simulating IEEE 802.11-operated WLANs. It achieves as much as two orders of magnitude improvement in terms of execution time as compared to packet-level simulation. The performance improvement is more pronounced when the number of wireless nodes, the number of applications running on each wireless node, or the number of WLANs increases. The relative error, on the other hand, falls within 2% in all cases, as long as the value of the time step is appropriately determined.","PeriodicalId":172626,"journal":{"name":"SIGMETRICS '04/Performance '04","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125603198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coping with network failures: routing strategies for optimal demand oblivious restoration","authors":"David Applegate, L. Breslau, E. Cohen","doi":"10.1145/1005686.1005719","DOIUrl":"https://doi.org/10.1145/1005686.1005719","url":null,"abstract":"Link and node failures in IP networks pose a challenge for network control algorithms. Routing restoration, which computes new routes that avoid failed links, involves fundamental tradeoffs between efficient use of network resources, complexity of the restoration strategy and disruption to network traffic. In order to achieve a balance between these goals, obtaining routings that provide good performance guarantees under failures is desirable.In this paper, building on previous work that provided performance guarantees under uncertain (and potentially unknown) traffic demands, we develop algorithms for computing optimal restoration paths and a methodology for evaluating the performance guarantees of routing under failures. We then study the performance of route restoration on a diverse collection of ISP networks. Our evaluation uses a competitive analysis type framework, where performance of routing with restoration paths under failures is compared to the best possible performance on the failed network. We conclude that with careful selection of restoration paths one can obtain restoration strategies that retain nearly optimal performance on the failed network while minimizing disruptions to traffic flows that did not traverse the failed parts of the network.","PeriodicalId":172626,"journal":{"name":"SIGMETRICS '04/Performance '04","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122126393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A game theoretic approach to provide incentive and service differentiation in P2P networks","authors":"Richard T. B. Ma, Sam C. M. Lee, John C.S. Lui, David K. Y. Yau","doi":"10.1145/1005686.1005711","DOIUrl":"https://doi.org/10.1145/1005686.1005711","url":null,"abstract":"Traditional peer-to-peer (P2P) networks do not provide service differentiation and incentive for users. Consequently, users can obtain services without themselves contributing any information or service to a P2P community. This leads to the \"free-riding\" and \"tragedy of the commons\" problems, in which the majority of information requests are directed towards a small number of P2P nodes willing to share their resources. The objective of this work is to enable service differentiation in a P2P network based on the amount of services each node has provided to its community, thereby encouraging all network nodes to share resources. We first introduce a resource distribution mechanism between all information sharing nodes. The mechanism is driven by a distributed algorithm which has linear time complexity and guarantees Pareto-optimal resource allocation. Besides giving incentive, the mechanism distributes resources in a way that increases the aggregate utility of the whole network. Second, we model the whole resource request and distribution process as a competition game between the competing nodes. We show that this game has a Nash equilibrium and is collusion-proof. To realize the game, we propose a protocol in which all competing nodes interact with the information providing node to reach Nash equilibrium in a dynamic and efficient manner. Experimental results are reported to illustrate that the protocol achieves its service differentiation objective and can induce productive information sharing by rational network nodes. Finally, we show that our protocol can properly adapt to different node arrival and departure events, and to different forms of network congestion.","PeriodicalId":172626,"journal":{"name":"SIGMETRICS '04/Performance '04","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122608041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance analysis of LAS-based scheduling disciplines in a packet switched network","authors":"Idris A. Rai, G. Urvoy-Keller, M. Vernon, E. Biersack","doi":"10.1145/1005686.1005702","DOIUrl":"https://doi.org/10.1145/1005686.1005702","url":null,"abstract":"The Least Attained Service (LAS) scheduling policy, when used for scheduling packets over the bottleneck link of an Internet path, can greatly reduce the average flow time for short flows while not significantly increasing the average flow time for the long flows that share the same bottleneck. No modification of the packet headers is required to implement the simple LAS policy. However, previous work has also shown that a drawback of the LAS scheduler is that, when link utilization is greater than 70%, long flows experience large jitter in their packet transfer times as compared to the conventional First-Come-First-Serve (FCFS) link scheduling. This paper proposes and evaluates new differentiated LAS scheduling policies that reduce the jitter for long flows that are identified as \"priority\" flows.To evaluate the new policies, we develop analytic models to estimate average flow transfer time as a function of flow size, and average packet transmission time as a function of position in the flow, for the single-bottleneck \"dumbbell topology\" used in many ns simulation studies. Models are developed for FCFS scheduling, LAS scheduling, and each of the new differentiated LAS scheduling policies at the bottleneck link. Over a wide range of configu-rations, the analytic estimates agree very closely with the ns estimates. Thus, the analytic models can be used instead of simulation for comparing the policies with respect to mean flow transfer time (as a function of flow size) and mean packet transfer time. Furthermore, an initial discrepancy between the analytic and simulation estimates revealed errors in the parameter values that are often specified in the widely used ns Web workload generator. We develop an improved Web workload specification, which is used to estimate the packet jitter for long flows (more accurately than with previous simulation workloads).Results for the scheduling policies show that a particular policy, LAS-log, greatly improves the mean flow transfer time for priority long flows while providing performance similar to LAS for the ordinary flows. Simulations show that the LAS-log policy also greatly reduces the jitter in packet delivery times for the priority flows.","PeriodicalId":172626,"journal":{"name":"SIGMETRICS '04/Performance '04","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130480518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multimedia streaming via TCP: an analytic performance study","authors":"B. Wang, J. Kurose, P. Shenoy, D. Towsley","doi":"10.1145/1005686.1005740","DOIUrl":"https://doi.org/10.1145/1005686.1005740","url":null,"abstract":"TCP is widely used in commercial media streaming systems, with recent measurement studies indicating that a significant fraction of Internet streaming media is currently delivered over HTTP/TCP. These observations motivate us to develop analytic performance models to systematically investigate the performance of TCP for both live and stored media streaming. We validate our models via ns simulations and experiments conducted over the Internet. Our models provide guidelines indicating the circumstances under which TCP streaming leads to satisfactory performance, showing, for example, that TCP generally provides good streaming performance when the achievable TCP throughput is roughly twice the media bitrate, with only a few seconds of startup delay.","PeriodicalId":172626,"journal":{"name":"SIGMETRICS '04/Performance '04","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133676378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of BGP dynamics on intra-domain traffic","authors":"S. Agarwal, C. Chuah, S. Bhattacharyya, C. Diot","doi":"10.1145/1005686.1005724","DOIUrl":"https://doi.org/10.1145/1005686.1005724","url":null,"abstract":"Recent work in network traffic matrix estimation has focused on generating router-to-router or PoP-to-PoP (Point-of-Presence) traffic matrices within an ISP backbone from network link load data. However, these estimation techniques have not considered the impact of inter-domain routing changes in BGP (Border Gateway Protocol). BGP routing changes have the potential to introduce significant errors in estimated traffic matrices by causing traffic shifts between egress routers or PoPs within a single backbone network. We present a methodology to correlate BGP routing table changes with packet traces in order to analyze how BGP dynamics affect traffic fan-out within a large \"tier-1\" network. Despite an average of 133 BGP routing updates per minute, we find that BGP routing changes do not cause more than 0.03% of ingress traffic to shift between egress PoPs. This limited impact is mostly due to the relative stability of network prefixes that receive the majority of traffic -- 0.05% of BGP routing table changes affect intra-domain routes for prefixes that carry 80% of the traffic. Thus our work validates an important assumption underlying existing techniques for traffic matrix estimation in large IP networks.","PeriodicalId":172626,"journal":{"name":"SIGMETRICS '04/Performance '04","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127290362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An evaluation of chord using traces of peer-to-peer file sharing","authors":"Jacky Chu, Kevin Labonte, B. Levine","doi":"10.1145/1005686.1005753","DOIUrl":"https://doi.org/10.1145/1005686.1005753","url":null,"abstract":"We evaluated the effectiveness of the Chord [1] as a protocol for file sharing using measurements from a real P2P application. Chord has several problems when used to support content sharing. The heavy-tail distributions we measured relating to queries and transfers results in a very unbalanced workload for Chord peers. Caches at nodes are helpful, but do not remove a unbalanced workload with a power-law skew. Our measurements are from a real P2P file-sharing protocol implementation based on a centralized architecture: users sent queries to a server that maintained a database of the current peers and their shared libraries. Users explicitly consented to our anonymized logging of their actions. Twice a day, a snapshot of users and their shared files was dumped Since we have a record of every query, and every transfer between users resulting from queries, the only information we are missing is the exact time when files in users’ libraries are added to the system out-of-band. This data revealed downloading habits of users that are independent of the underlying network file transferring architecture. We obtained a Chord simulator from the Chord project homepage [1].","PeriodicalId":172626,"journal":{"name":"SIGMETRICS '04/Performance '04","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130560828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A quantitative analysis of partitioning in mobile ad hoc networks","authors":"J. Hähner, D. Dudkowski, P. Marrón, K. Rothermel","doi":"10.1145/1005686.1005737","DOIUrl":"https://doi.org/10.1145/1005686.1005737","url":null,"abstract":"The performance of distributed algorithms in mobile ad hoc networks (MANETs) is strongly influenced by the connectivity of the network. In cases where the connectivity is low, network partitioning occurs, e.g., due to node mobility. In this paper we introduce a set of metrics that describe several characteristics of partitioning in mobile ad hoc networks. We have conducted an extensive simulation study for a wide range of network scenarios to show the impact of node mobility, density and transmission range on the proposed metrics. We present some of the results we obtained, i.e., for the average number of partitions and the rate at which the partition in which an individual node is contained in changes.","PeriodicalId":172626,"journal":{"name":"SIGMETRICS '04/Performance '04","volume":"231 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131564624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}