Real-time public group collaboration using IP multicast label filters

Internet based enterprise level collaboration tools enable organizations to make decisions faster and more accurately with less effort. However, these tools provide limited real-time group collaboration within and across organizations. Multicast protocols were developed to provide efficient group communication. This paper proposes a novel IP multicast network layer filter architecture that provides efficient and scalable real-time group collaboration between the required entities within an organization. This proposed network architecture uses a label filter mechanism to improve scalability and bandwidth for one-to-many and many-to-many real-time collaboration

Application Layer Anycast

In this paper, we present a new approach to application layer anycasting. The key to anycast is making it possible for clients to efficiently find the `best´ server for a given application in an unknown group of servers. The anycast service makes a wide range of new multimedia applications possible, and will be part of future integrated services networks. We designed a selective anycast protocol, which is aimed at picking the right server based on application specific metrics, such as network delay and server load. This paper considers server-choosing metrics and efficient mechanisms to compute these metrics. We also present simulation results, which show our approach´s merit, and proves that anycast can significantly improve the performance as compared to the traditional methods

Spatial Clustering for IP Multicast: Algorithms and an Application

We introduce spatial clustering of multicast group members as a mechanism to scale wide-area multicast-based applications. To motivate the use of such structures, we present a clustering based re-keying scheme for secure multicast. Using amortized analysis, we show that the communication, processing, and storage costs for this scheme to distribute keys upon membership changes is of constant order. This improves upon the previously known best-case logarithmic bounds under the same assumptions. Next, we develop a clustering algorithm and a cluster formation protocol that can be built atop IP multicast to create clusters with properties required to implement the secure multicast scheme. To show the viability of such a clustering scheme on the Internet, we present results from implementing this clustering technique on a Internet map of over 280,000 IP routers. We describe how a small set (~ 64) of multicast addresses can be used to efficiently implement intra-cluster communication in large groups (> 64K members). clustering protocol to demonstrate protocol robustness under varying membership dynamics

Study of architecture and protocols for reliable multicasting in packet switching networks

Group multicast protocols have been challenged to provide scalable solutions that meet the following requirements: (i) reliable delivery from different sources to all destinations within a multicast group; (ii) congestion control among multiple asynchronous sources. Although it is mainly a transport layer task, reliable group multicasting depends on routing architectures as well. This dissertation covers issues of both network and transport layers. Two routing architectures, tree and ring, are surveyed with a comparative study of their routing costs and impact to upper layer performances. Correspondingly, two generic transport protocol models are established for performance study. The tree-based protocol is rate-based and uses negative acknowledgment mechanisms for reliability control, while the ring-based protocol uses window-based flow control and positive acknowledgment schemes. The major performance measures observed in the study are network cost, multicast delay, throughput and efficiency. The results suggest that the tree architecture costs less at network layer than the ring, and helps to minimize latency under light network load. Meanwhile, heavy load reliable group multicasting can benefit from ring architecture, which facilitates window-based flow and congestion control. Based on the comparative study, a new two-hierarchy hybrid architecture, Rings Interconnected with Tree Architecture (RITA), is presented. Here, a multicast group is partitioned into multiple clusters with the ring as the intra-cluster architecture, and the tree as backbone architecture that implements inter-cluster multicasting. To compromise between performance measures such as delay and through put, reliability and congestion controls are accomplished at the transport layer with a hybrid use of rate and window-based protocols, which are based on either negative or positive feedback mechanisms respectively. Performances are compared with simulations against tree- and ring-based approaches. Results are encouraging because RITA achieves similar throughput performance as the ring-based protocol, but with significantly lowered delay. Finally, the multicast tree packing problem is discussed. In a network accommodating multiple concurrent multicast sessions, routing for an individual session can be optimized to minimize the competition with other sessions, rather than to minimize cost or delay. Packing lower bound and a heuristic are investigated. Simulation show that congestion can be reduced effectively with limited cost increase of routings

A Hierarchical Filtering-Based Monitoring Architecture for Large-scale Distributed Systems

On-line monitoring is essential for observing and improving the reliability and performance of large-scale distributed (LSD) systems. In an LSD environment, large numbers of events are generated by system components during their execution and interaction with external objects (e.g. users or processes). These events must be monitored to accurately determine the run-time behavior of an LSD system and to obtain status information that is required for debugging and steering applications. However, the manner in which events are generated in an LSD system is complex and represents a number of challenges for an on-line monitoring system. Correlated events axe generated concurrently and can occur at multiple locations distributed throughout the environment. This makes monitoring an intricate task and complicates the management decision process. Furthermore, the large number of entities and the geographical distribution inherent with LSD systems increases the difficulty of addressing traditional issues, such as performance bottlenecks, scalability, and application perturbation. This dissertation proposes a scalable, high-performance, dynamic, flexible and non-intrusive monitoring architecture for LSD systems. The resulting architecture detects and classifies interesting primitive and composite events and performs either a corrective or steering action. When appropriate, information is disseminated to management applications, such as reactive control and debugging tools. The monitoring architecture employs a novel hierarchical event filtering approach that distributes the monitoring load and limits event propagation. This significantly improves scalability and performance while minimizing the monitoring intrusiveness. The architecture provides dynamic monitoring capabilities through: subscription policies that enable applications developers to add, delete and modify monitoring demands on-the-fly, an adaptable configuration that accommodates environmental changes, and a programmable environment that facilitates development of self-directed monitoring tasks. Increased flexibility is achieved through a declarative and comprehensive monitoring language, a simple code instrumentation process, and automated monitoring administration. These elements substantially relieve the burden imposed by using on-line distributed monitoring systems. In addition, the monitoring system provides techniques to manage the trade-offs between various monitoring objectives. The proposed solution offers improvements over related works by presenting a comprehensive architecture that considers the requirements and implied objectives for monitoring large-scale distributed systems. This architecture is referred to as the HiFi monitoring system. To demonstrate effectiveness at debugging and steering LSD systems, the HiFi monitoring system has been implemented at the Old Dominion University for monitoring the Interactive Remote Instruction (IRI) system. The results from this case study validate that the HiFi system achieves the objectives outlined in this thesis

Smart network caches : localized content and application negotiated recovery mechanisms for multicast media distribution

Thesis (Ph. D.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 1998.Includes bibliographical references (p. 133-138).by Roger George Kermode.Ph.D

Sendmmsg: An Efficient System Call To Send Multiple Messages On Linux [sendmmsg: Uma Chamada De Sistema Eficiente Para Envio De Múltiplas Mensagens No Linux]

This article describes the limitations of sendmsg, the current system call responsible for sending network messages in Linux. It is shown that this system call performance is not good enough, mainly when it needs to send a batch of similar data to many destinations in the network, as commonly experienced in IPTV servers. In order to prove that, a new system call has been implemented, sendmmsg, which acts similarly to the original one, but presenting some performance advantages, specially when sending similar data to peers. This new call needs only an extra parameter, when compared to the original one. © 2011 IEEE.170175Araki, S., Bilas, A., Dubnicki, C., Edler, J., Konishi, K., Philbin, J., User-space communication: A quantitative study (1998) Proceedings of the 1998 ACM/IEEE Conference on Supercomputing (CDROM), Supercomputing '98, pp. 1-16. , Washington, DC, USA. IEEE Computer SocietyBlanchard, A., Net: Add Sendmmsg Socket System Call, 2011. , http://lwn.net/Articles/441169/, Acessado em 29/09/2011Franco, L., Sahama, T., Croll, P., Security enhanced Linux to enforce mandatory access control in health information systems (2008) Proceedings of the Second Australasian Workshop on Health Data and Knowledge Management, 80, pp. 27-33. , HDKM '08, Darlinghurst, Australia, Australia. Australian Computer Society, IncLahav, E., Karsten, M., Brecht, T., Wang, W., Zhao, T., Group unicast for the real world (2008) Proceedings of the 18th International Workshop on Network and Operating Systems Support for Digital Audio and Video, NOSSDAV '08, pp. 27-32. , New York, NY, USA. ACMLeitao, B., (2011) Breno's Repository, , https://github.com/leitao/Mestrado, Acessado em 29/09/2011Levine, B.N., Garcia-Luna-Aceves, J.J., Improving internet multicast with routing labels (1997) Proceedings of the 1997 International Conference on Network Protocols (ICNP '97), ICNP '97, p. 241. , Washington, DC, USA. IEEE Computer SocietyMukherjee, B., Brecht, T., Time-lined TCP for the TCP-friendly delivery of streaming media (2000) Proceedings of the 2000 International Conference on Network Protocols, ICNP '00, p. 165. , Washington, DC, USA. IEEE Computer SocietyRamirez, T., Pajuelo, A., Santana, O.J., Valero, M., Kilo-instruction processors, runahead and prefetching (2006) Proceedings of the 3rd Conference on Computing Frontiers 2006, CF '06, 2006, pp. 269-278. , DOI 10.1145/1128022.1128059, Proceedings of the 3rd Conference on Computing Frontiers 2006, CF '06Silverston, T., Fourmaux, O., Botta, A., Dainotti, A., Pescapé, A., Ventre, G., Salamatian, K., Traffic analysis of peer-to-peer IPTV communities (2009) Comput. Netw., 53, pp. 470-484Uhsadel, L., Georges, A., Verbauwhede, I., Exploiting hardware performance counters (2008) Proceedings of the 2008 5th Workshop on Fault Diagnosis and Tolerance in Cryptography, pp. 59-67. , Washington, DC, USA. IEEE Computer SocietyVlaovic, S., Davidson, E.S., Boosting trace cache performance with NonHead Miss Speculation (2002) Proceedings of the International Conference on Supercomputing, pp. 179-18