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290
MultiConstrained Optimal Path Selection
, 2001
"... Providing qualityofservice (QoS) guarantees in packet networks gives rise to several challenging issues. One of them is how to determine a feasible path that satisfies a set of constraints while maintaining high utilization of network resources. The latter objective implies the need to impose an a ..."
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Cited by 80 (1 self)
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Providing qualityofservice (QoS) guarantees in packet networks gives rise to several challenging issues. One of them is how to determine a feasible path that satisfies a set of constraints while maintaining high utilization of network resources. The latter objective implies the need to impose an additional optimality requirement on the feasibility problem. This can be done through a primary cost function (e.g., administrative weight, hopcount) according to which the selected feasible path is optimal. In general, multiconstrained path selection, with or without optimization, is an NPcomplete problem that cannot be exactly solved in polynomial time. Heuristics and approximation algorithms with polynomialand pseudopolynomialtime complexities are often used to deal with this problem. However, existing solutions suffer either from excessive computational complexities that cannot be used for online network operation or from low performance. Moreover, they only deal with special cases of the problem (e.g., two constraints without optimization, one constraint with optimization, etc.). For the feasibility problem under multiple constraints, some researchers have recently proposed a nonlinear cost function whose minimization provides a continuous spectrum of solutions ranging from a generalized linear approximation (GLA) to an asymptotically exact solution. In this paper, we propose an efficient heuristic algorithm for the most general form of the problem. We first formalize the theoretical properties of the above nonlinear cost function. We then introduce our heuristic algorithm (H MCOP), which attempts to minimize both the nonlinear cost function (for the feasibility part) and the primary cost function (for the optimality part). We prove that H MCOP guarantees at least t...
Traffic engineering with mpls in the internet
 IEEE Network Magazine
, 2000
"... This paper discusses Traffic Engineering with MultiProtocol Label Switching (MPLS) in an Internet Service Provider’s (ISP) network. In this paper, we first briefly review MPLS, Constraintbased Routing and enhanced link state Interior Gateway Protocols (IGPs) to provide a background for Traffic Eng ..."
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Cited by 57 (3 self)
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This paper discusses Traffic Engineering with MultiProtocol Label Switching (MPLS) in an Internet Service Provider’s (ISP) network. In this paper, we first briefly review MPLS, Constraintbased Routing and enhanced link state Interior Gateway Protocols (IGPs) to provide a background for Traffic Engineering. We then discuss the general issues of designing an MPLS system for Traffic Engineering. The design of GlobalCenter’s MPLS system is presented. Based on our experiences, a generic procedure for deploying MPLS system is proposed. We also discuss how to provide Quality of Service (QoS) in a network with MPLS. Putting these
Heuristic Search
, 2011
"... Heuristic search is used to efficiently solve the singlenode shortest path problem in weighted graphs. In practice, however, one is not only interested in finding a short path, but an optimal path, according to a certain cost notion. We propose an algebraic formalism that captures many cost notions ..."
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Cited by 46 (24 self)
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Heuristic search is used to efficiently solve the singlenode shortest path problem in weighted graphs. In practice, however, one is not only interested in finding a short path, but an optimal path, according to a certain cost notion. We propose an algebraic formalism that captures many cost notions, like typical Quality of Service attributes. We thus generalize A*, the popular heuristic search algorithm, for solving optimalpath problem. The paper provides an answer to a fundamental question for AI search, namely to which general notion of cost, heuristic search algorithms can be applied. We proof correctness of the algorithms and provide experimental results that validate the feasibility of the approach.
Network Policy Languages: A survey and a new approach
 Network, IEEE , Volume: 15 , Issue: 1 , Jan.Feb. 2001, pp10  21
, 2001
"... In this article a survey of current network policy languages is presented. Next, a summary of the techniques for detecting policy conflicts is given. Finally, a new language, PathBased Policy Language, which offers improvements to these is introduced. Previous network policy languages vary from the ..."
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Cited by 42 (0 self)
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In this article a survey of current network policy languages is presented. Next, a summary of the techniques for detecting policy conflicts is given. Finally, a new language, PathBased Policy Language, which offers improvements to these is introduced. Previous network policy languages vary from the very specific, using packet filters at the bit level, to the more abstract where concepts are represented, with implementation details left up to individual network devices. As background information a policy framework model and policybased routing protocols are discussed. PPL’s pathbased approach for representing network policies is advantageous in that quality of service and security policies can be associated with an explicit path through the network. This assignment of policies to network flows aids in new initiatives such as integrated services. The more stringent requirement of supporting pathbased policies can easily be relaxed with the use of wild card characters to also support differentiated services and besteffort service, which is provided by the Internet today.
An Efficient Algorithm for Finding a Path Subject to Two Additive Constraints
 Computer Communications Journal
, 2000
"... One of the key issues in providing endtoend qualityofservice (QoS) guarantees in packet networks is how to determine a feasible route that satisfies a set of constraints. In general, finding a path subject to multiple additive constraints (e.g., delay, delayjitter) is an NPcomplete problem ..."
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Cited by 33 (5 self)
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One of the key issues in providing endtoend qualityofservice (QoS) guarantees in packet networks is how to determine a feasible route that satisfies a set of constraints. In general, finding a path subject to multiple additive constraints (e.g., delay, delayjitter) is an NPcomplete problem that cannot be exactly solved in polynomial time. Accordingly, several heuristics and approximation algorithms have been proposed for this problem. Many of these algorithms suffer from either excessive computational cost or low performance. In this paper, we provide an efficient approximation algorithm for finding a path subject to two additive constraints. The worstcase computational complexity of this algorithm is within a logarithmic number of calls to Dijkstra's shortest path algorithm. Its average complexity is even much lower than that, as demonstrated by simulation experiments. The performance of the proposed algorithm is justified via theoretical bounds that are provided for ...
Evolution of the Internet QoS and support for soft realtime applications
 Swiss Federal Institute of Technology
, 2003
"... The past few years have witnessed the emergence of many realtime networked applications on the Internet. These types of applications require special support from the underlying network such as reliability, timeliness, and guaranteed delivery, as well as different levels of service quality. Unfortun ..."
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Cited by 31 (0 self)
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The past few years have witnessed the emergence of many realtime networked applications on the Internet. These types of applications require special support from the underlying network such as reliability, timeliness, and guaranteed delivery, as well as different levels of service quality. Unfortunately, this support is not available within the current “besteffort ” Internet architecture. In this paper, we review several mechanisms and frameworks proposed to provide network and applicationlevel quality of service (QoS) in the nextgeneration Internet. We first discuss the QoS requirements of many of the abovementioned realtime applications, and then we categorize them according to the required service levels. We also describe the various building blocks often used in QoS approaches. We briefly present asynchronous transfer mode (ATM) and Internet Protocol precedence. Then, we present and compare two service architectures recently adopted
Evaluation of Bandwidth Broker Signaling
 In IEEE Seventh International Conference on Network Protocols (ICNP
, 1999
"... The Differentiated Services (DiffServ) architecture for the Internet implements a scalable mechanism for qualityof service (QoS) provisioning. Bandwidth brokers represent the instances of the architecture, that automate the provisioning of a DiffServ service between network domains. Although severa ..."
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Cited by 24 (8 self)
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The Differentiated Services (DiffServ) architecture for the Internet implements a scalable mechanism for qualityof service (QoS) provisioning. Bandwidth brokers represent the instances of the architecture, that automate the provisioning of a DiffServ service between network domains. Although several bandwidth broker implementations (e.g. [1]) have been proposed, the alternatives and tradeoffs of the different viable approaches of interbroker communication were not studied up to now. This paper presents the broker signaling tradeoffs considered in the context of a DiffServ scenario used by the Swiss National Science Foundation project CATI [8], and it presents results gathered by simulations. 1 Introduction The DiffServ architecture (RFC 2475) uses automated bandwidth brokers [7] to negotiate service level agreements (SLA) between different autonomous systems. These agreements describe the volume of DiffServ traffic that can be exchanged between two domains and the price for that...
Precomputation for multiconstrained QoS routing in highspeed networks
 in INFOCOM ’03
, 2003
"... Abstract—As one of the most challenging problems of the nextgeneration highspeed networks, qualityof service routing (QoSR) with multiple (k) constraints is an NPcomplete problem. In this paper, we propose a multiconstrained energy functionbased precomputation algorithm, MEFPA. It cares each Q ..."
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Cited by 22 (3 self)
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Abstract—As one of the most challenging problems of the nextgeneration highspeed networks, qualityof service routing (QoSR) with multiple (k) constraints is an NPcomplete problem. In this paper, we propose a multiconstrained energy functionbased precomputation algorithm, MEFPA. It cares each QoS k −1 weight to b degrees, and computes a number (B = C b+ k −2) of coefficient vectors uniformly distributed in the kdimensional QoS metric space to construct B linear energy functions. Using each LEF, it then converts k QoS constraints to a single energy value. At last, it uses Dijkstra's algorithm to create B least energy trees, based on which the QoS routing table is created. We first analyze the performance of energy functions with k constraints, and give the method to determine the feasible and unfeasible areas for QoS requests in the kdimensional QoS metric space. We then introduce our MEFPA for kconstrained routing with the computation complexity of O(B(m+n+nlogn)). Extensive simulations show that, with few coefficient vectors, this algorithm performs well in both absolute performance and competitive performance. In conclusion, for its high scalability, high performance and simplicity, MEFPA is a promising QoSR algorithm in the nextgeneration highspeed networks. Keywords—QoS routing, precomputation, scalability, linear energy function, performance evaluation I.
NpBench: A benchmark suite for control plane and data plane applications for network processors,” inProc.ofICCD’03
, 2003
"... Modern network interfaces demand highly intelligent traffic management in addition to the basic requirement of wire speed packet forwarding. Several vendors are releasing network processors in order to handle these demands. Network workloads can be classified into data plane and control plane worklo ..."
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Cited by 22 (0 self)
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Modern network interfaces demand highly intelligent traffic management in addition to the basic requirement of wire speed packet forwarding. Several vendors are releasing network processors in order to handle these demands. Network workloads can be classified into data plane and control plane workloads, however most network processors are optimized for data plane. Also, existing benchmark suites for network processors primarily contain data plane workloads, which perform packet processing for a forwarding function. In this paper, we present a set of benchmarks, called NpBench, targeted towards control plane (e.g., traffic management, quality of service, etc.) as well as data plane workloads. The characteristics of NpBench workloads, such as instruction mix, parallelism, cache behavior and required processing capability per packet, are presented and compared with CommBench, an existing network processor benchmark suite [9]. We also discuss the architectural characteristics of the benchmarks having control plane functions, their implications to designing network processors and the significance of Instruction Level Parallelism (ILP) in network processors. 1.