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DOI: 10.1007/s10922-004-0676-1
Print publication date: 12/1/2004
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by Yang, Jiahai; Duan, Haixin; Wu, Jianping; Li, Xing

DOI: 10.1007/s10922-004-0670-7
Print publication date: 12/1/2004
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by Pessoa, Manuel; Alves, António; Quadros, Gonçalo; Boavida, Fernando; Henke, Michael; Natcheva, Milva; Halke, Patrick; Maurutschek, Peter; Huskic, Zenon; Wagner, Kurt; Zeppenfeldt, Frank; Donadio, Roberto

Several base elements for the provision of quality of service guarantees have been developed in the recent past. Of these, the Differentiated Services (DiffServ) architecture stands out as the most promising. In spite of this, various issues remain, especially when multidomain DiffServ services are concerned. In this case, some forms of distributed management of Service Level Agreements that allow the specification, exchange, enforcement and monitoring of quality of service data must be in place. Although, again, some isolated solutions exist for each of these problems, considerable effort is necessary to make them work together. The project presented in this paper tried to assess the feasibility of providing differentiated quality of service in satellite IP networks, by developing a dynamic Service Level Agreement management solution for an IP over Digital Video Broadcast Satellite system. The functionality of the implemented system comprises system configuration, dynamic SLA negotiation, QoS monitoring and metering, SLA conformance checking, and QoS reporting to customers.

DOI: 10.1007/s10922-004-0671-6
Print publication date: 12/1/2004
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by Bouras, Ch.; Gkamas, A.; Primpas, D.; Stamos, K.

This paper describes a Quality of Service (QoS) service on an IPv6 domain that aims to service aggregates of real-time traffic with minimum delay, jitter, and packet loss. It contains results from the tests that were performed in order to configure and evaluate the QoS mechanisms. As an actual example of real-time traffic, we have used the OpenH323 project, an open source H.323 implementation that has been ported to IPv6. The QoS mechanisms in IPv6 networks is still a field that has not been researched adequately, and we therefore present the results from the experiments in our IPv6 network that took advantage of the QoS mechanisms. This QoS service uses the Modular QoS CLI (MQC) mechanism and especially the Low Latency Queue feature (LLQ) in order to treat packets from real-time applications.

DOI: 10.1007/s10922-004-0672-5
Print publication date: 12/1/2004
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by Paik, Eun Kyoung; Cho, Hosik; Kwon, Taekyoung; Choi, Yanghee

Network mobility (NEMO) extends IP mobility to moving networks, which are groups of nodes that often constitute a subnet of a mobile router (MR). To realize this collective mobility, there are a number of important issues such as addressing and multihoming. With the proliferation of mobile nodes connected to the Internet, the efficient allocation/deallocation of addresses is becoming a vital requirement. We propose a collaborative address management scheme for network mobility, where the home DHCPv6 agent of a mobile network performs prefix delegation, while the mobile DHCPv6 agent (in the mobile network) allocates the IPv6 address to each mobile node. Also, network mobility with multiple MRs is taken into consideration. To provide a mobile network that has multiple MRs with robust Internet connectivity, we propose mobility-aware mobile router selection schemes. The concept of “mobility awareness” refers to the capability of a moving network in a vehicle (e.g., a train) to pinpoint the most stable Internet connectivity, by choosing the mobile router based on the vehicle’s movement pattern. The simulation shows that the proposed scheme outperforms a round-robin mobile router selection scheme in terms of the amount of carried traffic.

DOI: 10.1007/s10922-004-0673-4
Print publication date: 12/1/2004
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by Yi, Zhang; Yong, Zhang; Weinong, Wang

The administration of authorizations in an organization is a complex task. To ensure that tasks constituting the business processes are performed by authorized users, a proper authorization mechanism is required. Alturi and Huang have proposed a workflow authorization model and presented a color-timed Petri net based representation of their model. In this paper, we extend their model by using the colored Petri net formalism to model authorization management, security constraints like separation of duties, and role hierarchy in an elegant way to establish an integrated authorization management model. One of the great advantages of using Petri net formalism for system modeling is its strong mathematical foundation and the availability of a rich set of analysis techniques. Therefore, we will show in this paper the use of linear algebraic technique to analyze the reachable authorization states, and coverability graph to calculate the valid execution chains against the colored Petri net based workflow authorization management model.

DOI: 10.1007/s10922-004-0674-3
Print publication date: 12/1/2004
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by Tsolakou, Evi; Nikolouzou, Eugenia; Maniatis, Sotiris; Venieris, Iakovos

A vital requirement for next generation IP networks is the provision of services with differentiated behavior and characteristics. The basic reason for that is the need to provide Quality of Service (QoS) to the different types of user traffic produced by applications that are different in nature and behavior, analogously to the IP network services. The Differentiated Services (DiffServ) paradigm is still one of the major outcomes of the research community toward the provision of QoS to individual customer needs and applications. This paper addresses the definition and deployment of specific network services in a DiffServ environment. We reuse and extend the fundamental concepts of the Expedited Forwarding and Assured Forwarding per hop behaviors in order to define four new network services, apart from the well known Best Effort one, which introduce a specific traffic handling implementation along with an Admission Control methodology. These are analyzed and simulated in the paper in order to evaluate their performance and confirm the correctness of their fundamental principles.

DOI: 10.1007/s10922-004-0675-2
Print publication date: 12/1/2004
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DOI: 10.1007/s10922-004-1780-y
Print publication date: 12/1/2004
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by

DOI: 10.1007/s10922-004-0677-0
Print publication date: 12/1/2004
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DOI: 10.1007/s10922-004-1781-x
Print publication date: 12/1/2004
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