though the areas of secure multicast group architecture, key distribution, and sender authentication are under scrutiny, one topic that has not been explored is how to integrate these with multilevel security. Multile...
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ISBN:
(纸本)0780371283
though the areas of secure multicast group architecture, key distribution, and sender authentication are under scrutiny, one topic that has not been explored is how to integrate these with multilevel security. Multilevel security is the ability to distinguish subjects according to classification levels, which determines to what degree they can access confidential objects. In the case of groups, this means that some members can exchange messages at a higher sensitivity level than others. the Bell-La Padula model [1] outlines the rules of these multilevel accesses. In multicast groups that employ multilevel security, some of these rules are not desirable so a modified set of rules is developed in this paper and is termed differential security. Also, this paper proposes three methods to set up a differentially secure multicast group: (1) Naive approach, (2) Multiple tree differential security (DiffSec) approach, and (3) Single DiffSec tree approach. Our Simulation studies show that both Single and Multiple DiffSec tree approaches offer similar performance in terms of bandwidth consumption, which is significantly better than that of the Naive approach. We also discuss the suitability of the schemes taking into account scalability and implementation issues.
We consider the problem of how to achieve a simultaneous arrival of information at a multitude of recipients for applications where the receivers are noncooperative. For that reason, we aim at designing an inter-recei...
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ISBN:
(纸本)0780371283
We consider the problem of how to achieve a simultaneous arrival of information at a multitude of recipients for applications where the receivers are noncooperative. For that reason, we aim at designing an inter-receiver delay jitter fair service for Internet multicast delivery. In contrast to related work, we present an approach at application layer, which does not assume special properties of the core network nodes and can be partially deployed. All necessary functions except a trusted time service are handled in the end systems. At the receivers, a secure hardware performs the security related functions. Additionally, the approach implicitly takes current network load into account, which gives the opportunity to keep the message delivery delay low. An analysis and simulation of the approach shows that the resulting inter-receiver delay jitter can be reduced to the order of tens of milliseconds.
Recently many prominent web sites face so called distributed Denial of Service Attacks (DDoS). While former security threats could be faced by a tight security policy and ac-tive measures like using firewalls, vendor ...
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In this paper, we introduce a variety of mechanisms to enable scalable, adaptive, and reliable quality of service (QoS) guarantees across heterogeneous networking environments. the resultant scalable resource reservat...
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ISBN:
(纸本)0780371283
In this paper, we introduce a variety of mechanisms to enable scalable, adaptive, and reliable quality of service (QoS) guarantees across heterogeneous networking environments. the resultant scalable resource reservation scheme (SRRS) is the first resource management scheme that provides efficient fault protection based on the virtual reservation mechanism and a penalty-based adaptable reservation mechanism, so that QoS can continue to be guaranteed in the presence of faults without wasting expensive network resources unnecessarily. Based on the proposed geographical reservation mechanism and virtual IP addressing, SRRS can enable QoS guarantees in ad hoc mobile wireless networks. Also, resource reservation and allocation in SRRS are adaptive to the networking environments so that wireless QoS-guarantee issues can be resolved in the presence of mobility, making SRRS suitable for wireless mobile networks. We evaluate the performance of SRRS based on simulation and analysis, and show that SRRS can achieve considerably lower blocking rates as compared to previous reservation protocols.
Withthe recent advances in mobile computing, distributed organizations are facing a growing need for advanced Information and Communication Technologies (ICT) that support mobile working. the ability to use informati...
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ISBN:
(纸本)0769512690
Withthe recent advances in mobile computing, distributed organizations are facing a growing need for advanced Information and Communication Technologies (ICT) that support mobile working. the ability to use information effectively anywhere and anytime has become a key business success factor. Although many Computer Supported Collaborative Work (CSCW) systems have been introduced to date, technologies and architectures that support the collaboration of nomadic workers on a wide range of mobile devices, notebooks and personal computers is still a challenge. the MObile Teamwork Infrastructure for Organizations networking (MOTION)(1) project is aiming to design a highly flexible, open and scalable ICT architecture for mobile collaboration. In this paper;we present the mobile collaboration requirements of two MOTION industry, case studies, and highlight the advantages of a Web-based peer-to-peer architecture and for nomadic working.
Multicast communication enables a server to send content to multiple clients at the same time through a multicast tree. To deal withthe heterogeneity of client capacities, multiple multicast groups can be used to all...
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ISBN:
(纸本)0780371283
Multicast communication enables a server to send content to multiple clients at the same time through a multicast tree. To deal withthe heterogeneity of client capacities, multiple multicast groups can be used to allocate clients with similar capacity to the same group, so that the performance perceived by clients can be improved. In this paper, we investigate the problem of allocating clients to constrained multicast servers, which, similar to clients, have different capacities. We explore some interesting issues raised by the constraints and propose an optimal solution to the allocation problem. We evaluate the solution and show substantial performance gain of our algorithm over those considering the server constraints separately.
An error recovery scheme is essential for large-scale reliable multicast. In this paper, we design, implement, and evaluate an improved active error recovery scheme for reliable multicast (AERM). the AERM uses soft-st...
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ISBN:
(纸本)0780371283
An error recovery scheme is essential for large-scale reliable multicast. In this paper, we design, implement, and evaluate an improved active error recovery scheme for reliable multicast (AERM). the AERM uses soft-state storage to facilitate fast error recovery. It has the following features: a simple NAK suppression and aggregation mechanism, an efficient hierarchical RTT measurement mechanism, an effective local recover and scoped retransmission mechanism, and a periodical ACK mechanism We Implement the AERM and study its characteristics In NS2. We also compare performance with ARM[5] and AER/NCA[1], both of which are representative active reliable multicast protocols. the results indicate that AERM can achieve considerable performance improvement with limited support from routers. Our work also confirms that active networks can benefit some applications and become a promising network computing platform in the future.
Error recovery by retransmission for large scale multicast faces two intrinsic scalability challenges: acknowledgment implosion and exposure to retransmission. this paper proposes a new scheme to reduce the cost of er...
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ISBN:
(纸本)0780371283
Error recovery by retransmission for large scale multicast faces two intrinsic scalability challenges: acknowledgment implosion and exposure to retransmission. this paper proposes a new scheme to reduce the cost of error recovery by using the idea of cumulative negative acknowledgment (CNAK). In the scheme, we assume a window control of size W. A receiver does not send back a NAK immediately upon the discovery of a packet loss. Instead, the receiver accumulates the losses and returns a CNAK to the source at about half of the window interval. Retransmission is carried out on multiple multicast channels which are mapped to window size W. the A multicast channel is mapped to the sequence number i where i = 1,2,....W. Our scheme has the advantages: one CNAK replaces W/2 number of conventional NAKs, thus, greatly reducing the NAK overhead. Moreover, the use of multiple multicast channels for packet retransmission completely eliminates the exposure hazard. We apply the CNAK scheme to the DR local recovery model and show that the proposed C4 protocol is the most efficient protocol among all. the protocol is highly scalable and free of unwanted repair packets.
the explosive growth of the Internet, withthe emergence of new networking technologies and the increasing number of network-capable end devices, is paving the way for a number of novel distributed applications and se...
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the explosive growth of the Internet, withthe emergence of new networking technologies and the increasing number of network-capable end devices, is paving the way for a number of novel distributed applications and services. Cooperative distributed systems have become a common computing model, and pervasive computing has caught the interest of academia and industry. To support future network applications, we believe that new services need to be customizable, applications need to be dynamically extensible, and both applications and services should be able to adapt to variations in resource availability and demand. propose Active Streams (F.E. Bustamante and K. Schwan, 1999), a middleware approach and its associated framework for building distributed applications and services that exhibit these characteristics.
Many high-performance distributed applications use only a small fraction of their available bandwidth. A common cause of this problem is not a flaw in the application design, but rather improperly tuned network settin...
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Many high-performance distributed applications use only a small fraction of their available bandwidth. A common cause of this problem is not a flaw in the application design, but rather improperly tuned network settings. Proper tuning techniques, such as setting the correct TCP buffers and using parallel streams, are well-known in the networking community, but outside this community they are infrequently applied. In this paper, we describe a service that makes the task of network tuning trivial for application developers and users. Widespread use of this service should virtually eliminate a common stumbling block for high-performance distributed applications.
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