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Applications and the Internet, 2004. Proceedings. 2004 International Symposium on

Date 2004

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Displaying Results 1 - 25 of 63
  • Endpoint admission control enhanced systems for VoIP networks

    Page(s): 269 - 272
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (263 KB) |  | HTML iconHTML  

    This paper presents QoS control enhanced architecture for VoIP networks. In this architecture we use both the probe flow delay and average loss rate measurement systems. First we apply the probability-based EMBAC scheme on our delay system. Then we propose a new probability-based EMBAC with a severe congestion consideration scheme to improve the admission control scheme in both measurement systems. We compare the performance of the enhanced systems in terms of blocking probability under the same condition of achieving average packet loss rate no greater than the certain target by setting an appropriate admission threshold in each system under each scenario. In this study, it is shown through simulations that the enhanced systems proposed in this paper can be a powerful and reliable EMBAC tool for VoIP networks with minimum blocking probability and minimum average loss rates. View full abstract»

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  • Introducing grammar of the film language into automatic shooting for face-to-face meetings

    Page(s): 277 - 280
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (339 KB) |  | HTML iconHTML  

    In this paper, an automatic shooting method for face-to-face meeting scenes is proposed. Shooting a meeting scene requires multiple video cameras, and viewers may get confused when the shot switches between spatially distant video cameras. We introduce two filming languages - "imaginary line" and "camera triangle" - into an automatic shooting method. A prototype system is presented, and comparative experimental results demonstrate the benefits of our method. View full abstract»

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  • Interacting the Edutella/JXTA peer-to-peer network with Web services

    Page(s): 67 - 73
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (668 KB) |  | HTML iconHTML  

    Edutella/JXTA is a P2P (peer-to-peer) semantic Web application, which is aimed to accommodate heterogeneous resource metadata repositories in a P2P manner and further facilitate the exchange of the resource metadata based on RDF. Whereas the initial use cases of Edutella/JXTA are defined and implemented in the context of a pure P2P setting, where all Edutella participants are JXTA peers interacting with each other via various P2P services, in this paper we investigate the interaction between Edutella/JXTA and Web services with the purpose of exchanging distributed functionalities between the two platforms. In terms of two typical interaction scenarios: (1) exposing existing Edutella/JXTA P2P services as Web services; and (2) integrating Web services enabled content providers into Edutella/JXTA, we propose an approach for achieving the service layer interaction between Edutella/JXTA and Web services through so-called Web services/Edutella proxies. View full abstract»

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  • Remote visualization using resource monitoring technique for volume rendering of large datasets

    Page(s): 309 - 312
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (437 KB) |  | HTML iconHTML  

    We present a remote visualization using resource monitoring technique for volume rendering which breaks a large volume data into pieces (sub-volumes) so as to maintain volume rendering processing in physical memory in consideration of the available system resources. Each sub-volume is transferred to a rendering PC (personal computer), which performs hardware accelerated volume rendering and generates a partial image (sub-image). The sub-images are piled up in depth order to complete the final image. This technique has been applied to remote visualization of 3D finite element analysis result of 3D flow through a lateral saccular aneurysm, and we evaluated at remote places between Kyoto and Iwate. As a result, we showed that it is possible to perform rendering of large dataset that surpasses the available resource on the client side, and our technique was effective the remote visualization. View full abstract»

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  • A multi-dimensional packet classifier for NP-based firewalls

    Page(s): 250 - 254
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (246 KB) |  | HTML iconHTML  

    In this paper we present design and implementation of a new multi-dimensional packet classifier engine using network processor technology. Our classification algorithm is fast and is based on hierarchical trie search for multi-dimensional rules. Moreover, we propose a technique to optimize the memory usage of our classifier. We have used the Intel® IXP1200 network processor pipeline architecture for implementation of the classifier. The final system is targeted to be a fast firewall packet filtering engine that uses the filtering policies as its classification rules. Our experimental result shows that the packet classification throughput results for various distribution of packet sizes, is above 800Mbps. View full abstract»

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  • Performance measurement of mobile ad hoc network for application to Internet-ITS (intelligent transportation system)

    Page(s): 25 - 30
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (358 KB) |  | HTML iconHTML  

    We evaluated the performance of an ad hoc network in a mobile environment in order to access its feasibility as an infrastructure for vehicle-to-Internet communication services. To realize this kind of service. The infrastructure should provide wide range where the service is available. We expected that by using an ad hoc network, spatial service range, connection time to the access point while driving, and amount of data transferred from the access point would be better than in existing public wireless LAN services. In the experiment, three cars acted as mobile nodes, and we measured the connection time to the access point and the amount of data that could be given via the access point. The result confirms the feasibility of using an ad hoc network as an infrastructure for vehicle-to-Internet communication services. View full abstract»

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  • Change discovery of hierarchically structured, order-sensitive data in HTML/XML documents

    Page(s): 178 - 187
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (812 KB) |  | HTML iconHTML  

    As hierarchically structured, order-sensitive HTML/XML data become more prevailing in online data exchange and processing, discovering changes in these data is essential in Web data processing, especially when they evolve frequently over time. We propose a change-discovery algorithm (CDA) for any two HTML/XML documents, each of which is hierarchically structured and represented as an ordered tree. The novelties of CDA include (i) the usage of weighted sequence difference to determine the edit script with the anticipated minimal operational cost and (ii) the generation of the minimal contextual differences of branches in the two given trees. Differed from existing change-detection approaches that adopt node-to-node comparisons, CDA adopts branch-to-branch comparisons. Using CDA, generated edit scripts can be processed in any order to yield the same results, which enhances parallelism. CDA also guarantees lossless reversal transformation. The time complexity of CDA is polynomial, which is proportional to the numbers of branches in any two given trees. View full abstract»

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  • A distributed file system for Java Applet based distance learning

    Page(s): 145 - 151
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (261 KB) |  | HTML iconHTML  

    In our modern society, information literacy education for children in elementary school and junior high school is required. However, it can be difficult for these schools to effectively maintain a large number of PCs. In such cases, applet based educational content provided by ASP (application service provider) vendors can be useful. However, one problem with this approach is that applets cannot read or write local files. Therefore, we have developed a Java based distributed file system which is accessible from an applet. In this paper, we describe the design, implementation and evaluation of this distributed file system. View full abstract»

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  • A transparent session migration and transparent fail-over protocol for PPPoE server cluster

    Page(s): 255 - 261
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (253 KB) |  | HTML iconHTML  

    Recently, many LAN sockets service are provided in various areas. We presented the implementation and its evaluation of the authorized LAN socket system with PPPoE in previous works. Since most PCs have 100Mbps Ethernet port, one PPPoE server can only serve small number of clients because ordinary server has at most 1Gbps Ethernet port. To cope with this limitation, we adopt the clustering technology for the PPPoE server, but PPPoE protocol lacks the features for a reliable cluster such as dynamic load balancing and transparent fail-over. We propose a PPPoE client migration scheme that works without modifying the client PPPoE module. We also implemented a sample server to show the scheme is capable of constructing PPPoE cluster with transparent session migration and transparent fail-over. The key issues are using "per session MAC address" for each client session and sharing the client informations among all server components. Our experimental system shows only one second stall during migration, this is enough to the Internet applications such as Web browser and streaming real-video. View full abstract»

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  • A high presence shared space communication system using 2D background and 3D avatar

    Page(s): 50 - 55
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (517 KB) |  | HTML iconHTML  

    Displaying a 3D geometric model of a user in real-time has an advantage for a telecommunication system because depth information is useful for non-verbal communication such as finger-pointing and gestures that contain 3D information. However, a range image acquired by a rangefinder is suffered from errors due to image noises and distortions in depth measurement. On the other hand, a 2D image is free from such errors. In this paper, we propose a new method for a shared space communication system that combines advantages of both 2D and 3D representations. A user is represented as a 3D geometric model to exchange non-verbal communication cues. A background is displayed as a 2D image to give the user enough ideas about atmosphere of a remote site. We have constructed a prototype of a high presence shared space communication system to evaluate our method. In experiments, we have found that our proposed method is effective for telecommunication. View full abstract»

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  • Research directions for ubiquitous services

    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (189 KB) |  | HTML iconHTML  

    Summary form only given. This paper discusses the characteristics of ubiquitous services, their technical issues and research directions for the future. View full abstract»

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  • HTTP performance analysis over multi-hops satellite communication system

    Page(s): 107 - 113
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (366 KB) |  | HTML iconHTML  

    In order to provide a long distance communication such as the one between two nodes separated by about halfway around the earth, a multi-hops satellite communication system which goes through multiple satellites is attractive. Furthermore, in case of disasters, the system is useful as the alternative to submarine optical fiber links. HTTP1.1 (HyperText Transfer Protocol version 1.1) is one of the most popular protocols for obtaining files. However, the performance of HTTP1.1 on such multi-hops system has not sufficiently evaluated. Therefore, we evaluate Web data transfer time based on HTTP1.1 over the multi-hops satellite communication system. Firstly, we propose new formulas to evaluate the performance of both HTTP1.1 and pipelined HTTP1.1. Secondly, the calculation results derived from these formulas are compared with the experimental ones based on the SKYCAST system, which is one of the multihops satellite communication systems. As a result, in case of pipelined HTTP1.1, the comparison shows that the values based on the evaluation formula are close to those from the experimental results. However, we observed that the formula for HTTP1.1 with no pipeline underestimates the transfer time. Therefore, we have carefully investigated the data sequence using the output of tcpdump command. Based on the investigation, we have modified the proposed formulas. Consequently, it is clear that the improved formula well predicts the experimental results. View full abstract»

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  • A distributed real-time tool for IP-flow measurement

    Page(s): 91 - 98
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (559 KB) |  | HTML iconHTML  

    It is getting more difficult to monitor multiple services as well as to detect and/or to trace denial of service attacks with only tools showing graphs of the whole IP layer traffic like MRTG or by checking counters of router interfaces. In this paper, we discuss the specification of a software-based real-time measurement tool for flow which consists of multiple capture devices, a manager device and user interface devices, enabling flexible flow definition on demand without stopping system and working with IPv4 and/or IPv6, while also enabling high performance. With this discussion, we propose its architecture, bit-pattern-based flow definition method and data structure. Then we report on the performance evaluation of a prototype of proposed real-time flow measurement tools developed on PC-UNIXs and show that the number of bit-pattern composing flow definitions impact on the performance. Lastly we show an example of measuring flows in a real world environment and confirm that the flow extraction is simplified. View full abstract»

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  • A teleconferencing system with high-speed stream mixing for voice over IP

    Page(s): 295 - 298
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (286 KB) |  | HTML iconHTML  

    This paper presents a VoIP teleconferencing service that does not required expensive equipment and that can be administrated on a user level. The system is designed and developed so as to be independent of the user environment and to offer high QoS by reducing processing delay. This is achieved through the introduction of a high-speed mixing method to synchronize and mix RTP voice streams. The performance of a trial implementation of a teleconferencing server using this service is evaluated, and its effectiveness is confirmed. View full abstract»

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  • Realizing high mobility through an end-to-end network architecture with IP diversity support for real time Internet applications

    Page(s): 243 - 249
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (293 KB) |  | HTML iconHTML  

    This paper presents a mobile-controlled handoff with an end-to-end communication architecture that helps to provide high mobility without requiring any special service from the visiting networks. The handoff utilizes the IP diversity created by dual network interfaces at the mobile node and exploits the overlapping area between subnets. The end-to-end network architecture is particularly suitable for low bit rate delay sensitive real time applications, where payload tends to be short and packet header overhead is particularly significant. We describe the network architecture and show the mobility support by prototype implementation and its performance evaluation. We also develop an analytical model of handoff and compare the performance of handoff in proposed network architecture and mobile IPv6. Performance evaluation shows that the handoff quality not only depends on the location but also on the implementation design of the location database servers. We see significant latency improvement due to our implementation as compare to mobile IPv6. View full abstract»

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  • Performance analysis of content matching intrusion detection systems

    Page(s): 208 - 215
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (289 KB) |  | HTML iconHTML  

    Although network intrusion detection systems (nIDS) are widely used, there is limited understanding of how these systems perform in different settings and how they should be evaluated. This paper examines how nIDS performance is affected by traffic characteristics, rulesets, string matching algorithms and processor architecture. The analysis presented in this paper shows that nIDS performance is very sensitive to these factors. Evaluating a nIDS therefore requires careful consideration of a fairly extensive set of scenarios. Our results also highlight potential dangers with the use of workloads based on combining widely-available packet header traces with synthetic packet content as well as with the use of synthetic rulesets. View full abstract»

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  • Leveraging broadband access for true on-demand delivery of Internet videos

    Page(s): 171 - 177
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (275 KB) |  | HTML iconHTML  

    We consider in this paper how the increasingly popular broadband access can be leveraged for scalable and cost-effective video service. Although much work has been done for such service, the existing techniques either are not designed for on-demand video delivery, or do not take into account the vastly improved client receiving capability. In this paper, we address this problem and develop three novel video delivery techniques with two ultimate goals: minimizing service latency and maximize data sharing. With the new techniques, a client can be served as soon as server resource becomes available and meanwhile, all its receiving bandwidth can be used for data receiving. In particular, in the proposed dynamic scheduling algorithm, the efficiency of data sharing is further improved by also exploring server bandwidth for early delivery of video segments. This innovation is contradicted to the intuition that each video segment should be delivered as late as possible in order to maximize data sharing. We evaluate the performance of our new techniques using simulation and our study convincingly shows that with the new schemes, zero service latency can indeed be achieved with very minimal system resource. View full abstract»

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  • Path selection using active measurement in multi-homed wireless networks

    Page(s): 273 - 276
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (272 KB) |  | HTML iconHTML  

    The mobile Internet is built upon a number of different wireless access networks with widely varying features in terms of coverage area, bandwidth, packet loss, and delay. To move across these different networks smoothly, issues associated with the changing features need to be addressed. In this paper, a path selection method for the coverage overlap area is proposed in which the mobile host actively measures the round trip time (RTT) and bottleneck bandwidth for each path and a path is selected based on four rules. View full abstract»

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  • Ubiquitous computing and the Internet

    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (184 KB) |  | HTML iconHTML  

    Ubiquitous computing aims to embed small computer devices into every day objects to augment them with new functionality and to build an environment full of distributed computers. The interesting fusion of ubiquitous computing and the Internet promises a whole new area of thrilling applications and user interfaces. Examples are service relocation for mobile devices, access to real world objects and their functions in production process controls or home and office automation. View full abstract»

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  • Handling catastrophic failures in scalable Internet applications

    Page(s): 188 - 194
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (290 KB)  

    User perceived quality is the most important aspect of Internet applications. After a single negative experience, users tend to switch to one of the other myriad of alternatives available to them on the Internet. Two key components of Internet application quality are scalability and reliability. In this paper, we present the first general-purpose mechanism capable of maintaining reliability in the face of process, machine, and catastrophic failures. We define catastrophic failures as events that cause entire clusters of servers to become unavailable such as network partitioning, router failures, natural disasters, or even terrorist attacks. Our mechanism utilizes client-side tunneling, client-side redirection, and implicit redirection triggers to deliver reliable communication channels. We capitalize on previous work, redirectable sockets (RedSocks), that focuses on Internet application scalability. RedSocks are communication channels enhanced with a novel session layer aimed at modernizing network communication. We modify Red-Socks to create the first fault tolerant socket solution that can handle all server-side failures. Our mechanism is compatible with NATs and firewalls, scalable, application independent, and backwards compatible. View full abstract»

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  • Traffic analysis and worldwide operation of open 6to4 relays for IPv6 deployment

    Page(s): 265 - 268
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (239 KB) |  | HTML iconHTML  

    The 6to4 method enables separate IPv6 sites to connect to the IPv6 Internet via a 6to4 relay router without an explicit IPv6-over-IPv4 tunnel setup. We have been operating a 6to4 relay router in Japan since March 2002, and started operating another relay router in the US from June 2003. This paper provides an analysis of IPv6 traffic through our 6to4 relay router. We also propose a method for controlling paths of the 6to4 communication, and clarify its effect by demonstrating it on our worldwide 6to4 network in Japan and the US. View full abstract»

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  • Interactively adding Web service interfaces to existing Web applications

    Page(s): 74 - 80
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (288 KB) |  | HTML iconHTML  

    The World Wide Web is the largest database of the world - a huge amount of knowledge, information and services primarily intended for human users. Unfortunately, data on the Web requires intelligent interpretation and cannot be easily used by programs. It requires advanced data extraction and integration techniques to automatically process data. Lixto technology addresses these issues and enables developers to interactively turn Web pages into Web services. View full abstract»

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  • Clustering search engine query log containing noisy clickthroughs

    Page(s): 305 - 308
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (230 KB) |  | HTML iconHTML  

    Query clustering is a technique for discovering similar queries on a search engine. In this paper, we present a query clustering method based on the agglomerative clustering algorithm. We first present an overview of the agglomerative clustering algorithm proposed by Beeferman and Berger (2000). We point out a weakness of the method caused by noisy user clicks and propose an improved clustering algorithm. Our results show that in general the agglomerative clustering algorithm can cluster similar queries effectively and that our improved algorithm can successful eliminate noisy clicks and produce cleaner query clusters. View full abstract»

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  • DNS: disk-to-network splicing for network driven data transferring

    Page(s): 219 - 225
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (640 KB) |  | HTML iconHTML  

    In Internet servers that run on general-purpose operating systems, network subsystems and disk subsystems cooperate with each other for user requests. Many studies have focused on optimizing the data movement across the subsystems to reduce data copying overhead among intermediate buffers such as process buffers, network send buffers and disk buffers. When data are moved across the subsystems, events such as read requests and write requests for data movement are also delivered across the subsystems by the servers and operating systems. However, there have been fewer studies on the optimization of event delivery which controls data copying timing across the subsystems. In conventional operating systems, to transfer data in the disk subsystem into the network subsystem, several different contexts are involved. A series of events are passed through the contexts. Whenever an event in one context is passed into the other context, context switching and scheduling are incurred. We have developed inter-subsystem event delivery mechanism, disk-to-network splicing (DNS), which optimizes event delivery among the subsystems involved to suppress scheduling and context switching during I/O request processing. We developed a DNS mechanism and performed experiments on Linux 2.4. The experimental results show that the system performance is improved by 4.9% 10.1%. View full abstract»

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  • e-MulCS: multi-party conference system with virtual space and the intuitive input interface

    Page(s): 56 - 63
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (814 KB) |  | HTML iconHTML  

    Currently, multi-party video conference does not provide equivalent quality in comparison to face-to-face conference. One assumed reason is that participants cannot be aware of "who is focusing on whom". We introduce virtual space to a multi-party conference system, allocating avatars in a space. We also introduce intuitive input interface using motion processor in order to construct a multi-party conference system, which the user can use without being aware of it. A new displaying method is essential for this system, and we introduce a way by which a user can obtain the feedback of which user he/she is focusing on. We introduce e-MulCS as the system that fulfils these proposals. By comparing this system with the video conference system, the results show that our system supports the intuitive multi-party communication better. View full abstract»

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