Pub Date : 2002-07-01DOI: 10.1109/ISCC.2002.1021666
C. Bewick, R. Pereira, M. Merabti
Interactive multimedia applications over multi-hop cell or packet-switched networks have strict bounds on delay, loss, and jitter. Much research has focused on how best to handle the networking issues related to supporting quality of service (QoS) contracts without compromising network efficiency, i.e. improving network utilisation, and reducing connection packet loss and late delivery. This paper describes our novel technique, network constrained smoothing, for smoothing video traffic into a server-side transmission schedule. Our approach combines QoS metrics about video connections together with network loading information in an algorithm that divides the schedule into equal-sized intervals of constant bit-rate. We evaluate performance by simulation and compare with an existing smoothing technique, optimal smoothing. We show the benefits of using network constrained smoothing to synchronise independent multimedia streams. The results show reductions in network loading at peak times and provide manageable information for routers about currently supported multimedia traffic.
{"title":"Network constrained smoothing: enhanced multiplexing of MPEG-4 video","authors":"C. Bewick, R. Pereira, M. Merabti","doi":"10.1109/ISCC.2002.1021666","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021666","url":null,"abstract":"Interactive multimedia applications over multi-hop cell or packet-switched networks have strict bounds on delay, loss, and jitter. Much research has focused on how best to handle the networking issues related to supporting quality of service (QoS) contracts without compromising network efficiency, i.e. improving network utilisation, and reducing connection packet loss and late delivery. This paper describes our novel technique, network constrained smoothing, for smoothing video traffic into a server-side transmission schedule. Our approach combines QoS metrics about video connections together with network loading information in an algorithm that divides the schedule into equal-sized intervals of constant bit-rate. We evaluate performance by simulation and compare with an existing smoothing technique, optimal smoothing. We show the benefits of using network constrained smoothing to synchronise independent multimedia streams. The results show reductions in network loading at peak times and provide manageable information for routers about currently supported multimedia traffic.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129301022","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}
Pub Date : 2002-07-01DOI: 10.1109/ISCC.2002.1021759
G. Samaras, Constantinos Spyrou, E. Pitoura
The View Generator (VG) is a system that provides the necessary components for the definition, materialization, storage, maintenance and re-use of views over remote Web-accessible databases. Through the system, clients identify Web databases of interest, access their metadata and create personalized views that can be shared by other clients. Creating personalized views provides a more efficient way of data processing than directly issuing complex queries to the data sources especially in the case of lightweight and wireless clients that suffer from scarce local resources, limited bandwidth and high communication costs. VG's multi-tier architecture implemented using mobile Java agents allows automatic code deployment as well as dynamic relocation of views.
{"title":"View Generator (VG): a mobile agent based system for the creation and maintenance of Web views","authors":"G. Samaras, Constantinos Spyrou, E. Pitoura","doi":"10.1109/ISCC.2002.1021759","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021759","url":null,"abstract":"The View Generator (VG) is a system that provides the necessary components for the definition, materialization, storage, maintenance and re-use of views over remote Web-accessible databases. Through the system, clients identify Web databases of interest, access their metadata and create personalized views that can be shared by other clients. Creating personalized views provides a more efficient way of data processing than directly issuing complex queries to the data sources especially in the case of lightweight and wireless clients that suffer from scarce local resources, limited bandwidth and high communication costs. VG's multi-tier architecture implemented using mobile Java agents allows automatic code deployment as well as dynamic relocation of views.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130731460","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}
Pub Date : 2002-07-01DOI: 10.1109/ISCC.2002.1021703
J. Ye, S. Papavassiliou, G. Anastasi, A. Puliafito
We propose an integrated solution for QoS management in mobile wireless networks that can be dynamically adapted to user requirements and resource availability. Due to the strong variability of the environment under examination, we propose to use mobile agents as the underlying enabling technology. We propose a proactive approach that tries to satisfy the user requirements by utilizing advance resource reservations, and a reactive approach which tries to negotiate network resources when significative changes in the demand of resources arise. We also propose a combination of the two approaches in an integrated hybrid system that combines a mobility predictive advanced bandwidth reservation scheme with a call admission control and resource reconfiguration strategy to support flexible QoS management.
{"title":"Strategies for dynamic management of the QoS of mobile users in wireless networks through software agents","authors":"J. Ye, S. Papavassiliou, G. Anastasi, A. Puliafito","doi":"10.1109/ISCC.2002.1021703","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021703","url":null,"abstract":"We propose an integrated solution for QoS management in mobile wireless networks that can be dynamically adapted to user requirements and resource availability. Due to the strong variability of the environment under examination, we propose to use mobile agents as the underlying enabling technology. We propose a proactive approach that tries to satisfy the user requirements by utilizing advance resource reservations, and a reactive approach which tries to negotiate network resources when significative changes in the demand of resources arise. We also propose a combination of the two approaches in an integrated hybrid system that combines a mobility predictive advanced bandwidth reservation scheme with a call admission control and resource reconfiguration strategy to support flexible QoS management.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130692970","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}
Pub Date : 2002-07-01DOI: 10.1109/ISCC.2002.1021773
Zici Zheng, R. Kinicki
Using ns-2 simulations, this paper evaluates an adaptive explicit congestion notification (AECN) router. By receiving round-trip time (RTT) source hints from each TCP flow, AECN divides flows into flow groups based on RTT ranges. AECN uses distinct flow group drop probabilities and a mark front scheme to provide higher goodput and better fairness than random early detection (RED) and explicit congestion notification (ECN) routers.
{"title":"Adaptive explicit congestion notification","authors":"Zici Zheng, R. Kinicki","doi":"10.1109/ISCC.2002.1021773","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021773","url":null,"abstract":"Using ns-2 simulations, this paper evaluates an adaptive explicit congestion notification (AECN) router. By receiving round-trip time (RTT) source hints from each TCP flow, AECN divides flows into flow groups based on RTT ranges. AECN uses distinct flow group drop probabilities and a mark front scheme to provide higher goodput and better fairness than random early detection (RED) and explicit congestion notification (ECN) routers.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131170336","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}
Pub Date : 2002-07-01DOI: 10.1109/ISCC.2002.1021676
Markus Debusmann, M. Schmid, R. Kröger
The Common Object Request Broker Architecture (CORBA) is often used as backbone middleware for connecting critical business system components and for integrating legacy systems. Therefore, CORBA applications have to be managed in an efficient manner. The emerging trend of service level agreements and service level management requires the management of a system from an end-user's viewpoint, i.e., metrics like application response time and availability are key concerns. This requires a very fine-grained monitoring of the application in order to identify its performance-critical parts. This paper presents a new generic instrumentation approach for CORBA applications that enables the measurement of end-to-end performance characteristics. The measurements are very fine-grained, i.e., complex invocation hierarchies within object meshes can be monitored. The presented solution is based on portable interceptors and the application response measurement (ARM).
{"title":"Measuring end-to-end performance of CORBA applications using a generic instrumentation approach","authors":"Markus Debusmann, M. Schmid, R. Kröger","doi":"10.1109/ISCC.2002.1021676","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021676","url":null,"abstract":"The Common Object Request Broker Architecture (CORBA) is often used as backbone middleware for connecting critical business system components and for integrating legacy systems. Therefore, CORBA applications have to be managed in an efficient manner. The emerging trend of service level agreements and service level management requires the management of a system from an end-user's viewpoint, i.e., metrics like application response time and availability are key concerns. This requires a very fine-grained monitoring of the application in order to identify its performance-critical parts. This paper presents a new generic instrumentation approach for CORBA applications that enables the measurement of end-to-end performance characteristics. The measurements are very fine-grained, i.e., complex invocation hierarchies within object meshes can be monitored. The presented solution is based on portable interceptors and the application response measurement (ARM).","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127353573","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}
Pub Date : 2002-07-01DOI: 10.1109/ISCC.2002.1021688
R. Kilany, A. Serhrouchni
This paper presents a novel active architecture for building and deploying network services: HABA, hyper active components architecture. At the architectural level, HABA defines an active node whose functionalities are divided into the node operating system, the execution environment, and the active applications. At the implementation level, HABA is a component-based platform where new components could be added and deployed, in order to modify network node behavior dynamically. Applications can communicate across multi-tiered heterogeneous environments, and across Internet and intranet structures. Interoperability with ANTS is achieved by "composition". At the deployment level, HABA uses an active node approach, and offers a parallel controlled deployment mode and a sequential by request mode. In terms of security, HABA offers different security levels according to service profiles. Authentication of deployed code, and protection of nodes, is achieved by the deployment of certificates on the nodes.
{"title":"Using distributed component model for active service deployment","authors":"R. Kilany, A. Serhrouchni","doi":"10.1109/ISCC.2002.1021688","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021688","url":null,"abstract":"This paper presents a novel active architecture for building and deploying network services: HABA, hyper active components architecture. At the architectural level, HABA defines an active node whose functionalities are divided into the node operating system, the execution environment, and the active applications. At the implementation level, HABA is a component-based platform where new components could be added and deployed, in order to modify network node behavior dynamically. Applications can communicate across multi-tiered heterogeneous environments, and across Internet and intranet structures. Interoperability with ANTS is achieved by \"composition\". At the deployment level, HABA uses an active node approach, and offers a parallel controlled deployment mode and a sequential by request mode. In terms of security, HABA offers different security levels according to service profiles. Authentication of deployed code, and protection of nodes, is achieved by the deployment of certificates on the nodes.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"216 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113980667","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}
Pub Date : 2002-07-01DOI: 10.1109/ISCC.2002.1021660
R. Ammar, A. Alhamdan
Scheduling a large number of high performance computing applications on a cluster-computing environment is a complex task. This becomes more critical in real time systems. Efficient scheduling strategies are critically important to achieving good performance. A cluster scheduler without enough knowledge of the state of the cluster and the scheduled tasks cannot adequately manage the cluster resources. Accordingly, the available processing power of the participating nodes may experience uncontrolled fragmentation. Thus, some of the submitted applications may be rejected due to tasks missing their deadlines. The literature on scheduling real-time task graphs is much less extensive, especially for providing timing guarantees while maximizing the processing power utilization. In this paper, we present a framework for allocating and scheduling real-time applications represented as parallel task graphs on a cluster. We utilize the available processing power on each processor to accommodate as many tasks as possible while satisfying the required deadline of each task. The algorithm also reduces the communication cost among tasks and the possibility of processing power fragmentation.
{"title":"Scheduling real time parallel structure on cluster computing","authors":"R. Ammar, A. Alhamdan","doi":"10.1109/ISCC.2002.1021660","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021660","url":null,"abstract":"Scheduling a large number of high performance computing applications on a cluster-computing environment is a complex task. This becomes more critical in real time systems. Efficient scheduling strategies are critically important to achieving good performance. A cluster scheduler without enough knowledge of the state of the cluster and the scheduled tasks cannot adequately manage the cluster resources. Accordingly, the available processing power of the participating nodes may experience uncontrolled fragmentation. Thus, some of the submitted applications may be rejected due to tasks missing their deadlines. The literature on scheduling real-time task graphs is much less extensive, especially for providing timing guarantees while maximizing the processing power utilization. In this paper, we present a framework for allocating and scheduling real-time applications represented as parallel task graphs on a cluster. We utilize the available processing power on each processor to accommodate as many tasks as possible while satisfying the required deadline of each task. The algorithm also reduces the communication cost among tasks and the possibility of processing power fragmentation.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114309062","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}
Pub Date : 2002-07-01DOI: 10.1109/ISCC.2002.1021705
S. Andreozzi
This paper aims to provide a proof of concept of the accuracy of simulations for studying advanced networking. The particular target technology is the differentiated services (DiffServ) architecture. The method has been to apply experimental activities conducted in a real network to a simulation environment, to gather the same performance parameters and to compare results. A worthy re-engineering of the DiffServ module of the deployed software program has been carried out and significant contribution have been made to overcome the encountered limitations and to enrich its modeling capabilities. Final results give useful suggestions for a more critical approach to simulations targeted at studying advanced networking.
{"title":"Differentiated services: an experimental vs. simulated case study","authors":"S. Andreozzi","doi":"10.1109/ISCC.2002.1021705","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021705","url":null,"abstract":"This paper aims to provide a proof of concept of the accuracy of simulations for studying advanced networking. The particular target technology is the differentiated services (DiffServ) architecture. The method has been to apply experimental activities conducted in a real network to a simulation environment, to gather the same performance parameters and to compare results. A worthy re-engineering of the DiffServ module of the deployed software program has been carried out and significant contribution have been made to overcome the encountered limitations and to enrich its modeling capabilities. Final results give useful suggestions for a more critical approach to simulations targeted at studying advanced networking.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130093639","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}
Pub Date : 2002-07-01DOI: 10.1109/ISCC.2002.1021683
Maria Barra, A. Lannaccone, Giuseppina Palmieri, V. Scarano
We present an adaptive system for training and teaching. Our system integrates an adaptive training environment and a cooperative environment for exams both accessible via Internet by standard Java-enabled browsers. In this paper we present details on the architecture, describe the project with regard to the adaptive self-training part, and report on an experiment that demonstrates the effectiveness of the strategy: to draw attention of students to the topics they need to study. We experimented the system in a real case study with students attending a first year course, "Laboratorio di Informatica" of the Laurea degree in computer science in our University.
我们提出了一个适应性的培训和教学系统。我们的系统集成了一个自适应的训练环境和一个协作的考试环境，这两个环境都可以通过标准的支持java的浏览器通过互联网访问。在本文中，我们详细介绍了该策略的架构，描述了关于自适应自我训练部分的项目，并报告了一个实验，证明了该策略的有效性:将学生的注意力吸引到他们需要学习的主题上。我们在一个真实的案例研究中对这个系统进行了实验，研究对象是参加我们大学计算机科学Laurea学位一年级课程“laboratoro di Informatica”的学生。
{"title":"Test++: an adaptive training system on the Internet","authors":"Maria Barra, A. Lannaccone, Giuseppina Palmieri, V. Scarano","doi":"10.1109/ISCC.2002.1021683","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021683","url":null,"abstract":"We present an adaptive system for training and teaching. Our system integrates an adaptive training environment and a cooperative environment for exams both accessible via Internet by standard Java-enabled browsers. In this paper we present details on the architecture, describe the project with regard to the adaptive self-training part, and report on an experiment that demonstrates the effectiveness of the strategy: to draw attention of students to the topics they need to study. We experimented the system in a real case study with students attending a first year course, \"Laboratorio di Informatica\" of the Laurea degree in computer science in our University.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"312 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122815067","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}
Pub Date : 2002-07-01DOI: 10.1109/ISCC.2002.1021784
Emre Yetginer, Ezhan Karasan
In this paper we study traffic engineering of restorable paths in multiprotocol label switching (MPLS) networks. We consider off-line computation of working and restoration paths with path rerouting as the restoration scheme. First we compute a link-disjoint path set for given set of demands. Using this path set we study four approaches for selecting working and restoration paths, and formulate each method as an integer linear programming (ILP) problem. A traffic uncertainty model is developed in order to compare these approaches based on their robustness with respect to changing traffic patterns. We obtain numerical results and compare these design approaches based on the number of additional demands carried and the distribution of residual capacity over the network.
{"title":"Robust path design algorithms for traffic engineering with restoration in MPLS networks","authors":"Emre Yetginer, Ezhan Karasan","doi":"10.1109/ISCC.2002.1021784","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021784","url":null,"abstract":"In this paper we study traffic engineering of restorable paths in multiprotocol label switching (MPLS) networks. We consider off-line computation of working and restoration paths with path rerouting as the restoration scheme. First we compute a link-disjoint path set for given set of demands. Using this path set we study four approaches for selecting working and restoration paths, and formulate each method as an integer linear programming (ILP) problem. A traffic uncertainty model is developed in order to compare these approaches based on their robustness with respect to changing traffic patterns. We obtain numerical results and compare these design approaches based on the number of additional demands carried and the distribution of residual capacity over the network.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128810233","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}
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