Optimal capacity placement for path restoration in STM or ATM mesh-survivable networks
TL;DR: A method for capacity optimization of path restorable networks which is applicable to both synchronous transfer mode (STM) and asynchronous transfermode (ATM) virtual path (VP)-based restoration and jointly optimizing working path routing and spare capacity placement.
Abstract: The total transmission capacity required by a transport network to satisfy demand and protect it from failures contributes significantly to its cost, especially in long-haul networks. Previously, the spare capacity of a network with a given set of working span sizes has been optimized to facilitate span restoration. Path restorable networks can, however, be even more efficient by defining the restoration problem from an end to end rerouting viewpoint. We provide a method for capacity optimization of path restorable networks which is applicable to both synchronous transfer mode (STM) and asynchronous transfer mode (ATM) virtual path (VP)-based restoration. Lower bounds on spare capacity requirements in span and path restorable networks are first compared, followed by an integer program formulation based on flow constraints which solves the spare and/or working capacity placement problem in either span or path restorable networks. The benefits of path and span restoration, and of jointly optimizing working path routing and spare capacity placement, are then analyzed.
Citations
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30 Dec 2008
TL;DR: Using this method, not only the result by the current methods, but also a link capacity assignment result with minimum network delay can be obtained, which meets the restrictive conditions of link delay differences and link capacities.
Abstract: Link circuit capacity and delay are one of the principal problems in computer network topological design. Many different methods have been put forth. The paper gives a new method to assign link circuit capacity on the base of L. Kleinroek's. This method is quit different from the current one of Bernd mister, carul A. Niznik, No alpha parameter introduced and no group algorithm used in the model, but quantitative analysis from the very beginning to the end of and a strict integrated mathematical model is set up, which is fit for various conditions. Using this method, not only the result by the current methods, but also a link capacity assignment result with minimum network delay can be obtained, which meets the restrictive conditions of link delay differences and link capacities.
17 Oct 2005
TL;DR: This paper presents a restoration technique for recovering the label-switched paths (LSPs) in MPLS networks, where a variety of services with heterogeneous QoS requirements are supported.
Abstract: This paper presents a restoration technique for recovering the label-switched paths (LSPs) in MPLS networks, where a variety of services with heterogeneous QoS requirements are supported. A scheduling mechanism is designed for sending the failure notification messages of various priority LSPs. It ensures better routes and preferential resource access for the higher priority LSPs, and achieves acceptable recovery time for lower priority LSPs at the same time. Simulation results show that the proposed scheduling mechanism achieves significant performance improvement in terms of the LSP restoration time. Our approach is feasible for the restoration of the MPLS networks and any other connection-oriented packet networks
Cites background from "Optimal capacity placement for path..."
...Network survivability issue has gained much research effort in the recent years, such as, optimization of the network capacity usage [8, 11, 13], improvement of restoration path selection algorithms [9, 10, 12], and the failure notification mechanisms [2, 3, 4]....
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21 Jun 2007
TL;DR: This paper designs almost best possible approximation algorithms for the underlying optimization problem is NP hard and shows that they work well in practice as well in the context of MPLS fast reroute when protection capacities are pre-provisioned.
Abstract: Network QoS is essential for supporting real time interactive services such as VoIP. In the differentiated services framework QoS is provided by marking packets to receive preferential forwarding treatment, at each network node. This per hop forwarding treatment at each node may however be ineffective in providing the delay and jitter guarantees unless bounds are also imposed on the number of hops in the service routing paths. Interactive services also require minimal interruptions from network disruptions. Routing on hop limited paths may however have an adverse impact on the proportion of network capacity dedicated for protection to guarantee recovery from failures. In this paper we analyze this tradeoff in the context of MPLS fast reroute when protection capacities are pre-provisioned. We show that the underlying optimization problem is NP hard. We design almost best possible approximation algorithms for the problem and show that they work well in practice as well.
TL;DR: In this article, the authors propose a pre-cross-connected trail (PXT) structure that is more flexible than rings and adapts readily to both path-based and link-based protection schemes and to both static and dynamic traffic.
Abstract: Conventional optical networks are based on SONET rings, but since rings are known to use bandwidth inefficiently, there has been much research into shared mesh protection, which promises significant bandwidth savings. Unfortunately, most shared mesh protection schemes cannot guarantee that failed traffic will be restored within the 50 ms timeframe that SONET standards specify. A notable exception is the p-cycle scheme of Grover and Stamatelakis. We argue, however, that p-cycles have certain limitations, e.g., there is no easy way to adapt p-cycles to a path-based protection scheme, and p-cycles seem more suited to static traffic than to dynamic traffic. In this paper we show that the key to fast restoration times is not a ring-like topology per se, but rather the ability to pre-cross-connect protection paths. This leads to the concept of a pre-cross-connected trail or PXT, which is a structure that is more flexible than rings and that adapts readily to both path-based and link-based schemes and to both static and dynamic traffic. The PXT protection scheme achieves fast restoration speeds, and our simulations, which have been carefully chosen using ideas from experimental design theory, show that the bandwidth efficiency of the PXT protection scheme is comparable to that of conventional shared mesh protection schemes.
TL;DR: A fast heuristic algorithm named Multi-Modular Optimal Capacity (MMOC) is proposed, which has low time complexity and good performance near to the ILP results.
Abstract: In this paper, we propose a novel multi-modular optimal capacity algorithm for SDH (Synchronous Digital Hierarchy) mesh networks. Our objective is to minimize total capital cost of the SDH mesh networks with modularity. First, the optimization problem is formulated as an integer linear programming (ILP) model. Then considering the time complexity of ILP formulation for large-scale networks, a fast heuristic algorithm named Multi-Modular Optimal Capacity (MMOC) is proposed. Several network models, which serve as test cases, are provided and the numerical results show our heuristic algorithm has low time complexity and good performance (in terms of network cost) near to the ILP results.
References
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Book•
16 Feb 1970
TL;DR: Interestingly, integer programming and network flows that you really wait for now is coming, it's significant to wait for the representative and beneficial books to read.
Abstract: (1970). Integer Programming and Network Flows. Journal of the Operational Research Society: Vol. 21, No. 4, pp. 500-501.
638 citations
TL;DR: Self-healing network techniques suitable for ATM networks in order to realize a high-reliablity B-ISDN are proposed and high-speed restoration technique which exploits the benefits of the VP is proposed and described.
Abstract: This paper proposes self-healing network techniques suitable for ATM networks in order to realize a high-reliablity B-ISDN. First, the characteristics of the virtual paths (VP) and their influence on failure restoration are discussed. A high-speed restoration technique which exploits the benefits of the VP is then proposed and described. The technique simplifies the message transmission processes and reduces the number of generated messages by using preassigned backup virtual paths. Next, the scheme used to design the backup VP routes and spare resource distribution for each link is proposed in order to create a network that applies the proposed restoration scheme. Next, self-reconstruction techniques of backup virtual paths are proposed for the realization of a reversionless restoration cycle. Finally, the feasibility of the distributed control operation is discussed. >
233 citations
TL;DR: A comparative study of the effectiveness of KSP versus Max Flow as an alternative rerouting criteria in the context of transport network span restoration, and the hypothesis is made that a generalized "trap" topology is responsible for all KSP-Max Flow capacity differences.
Abstract: In the development of technologies for span failure restoration, a question arises about the restoration rerouting characteristics to be specified. In theory, maximal rerouting capacity is obtained with a maximum flow (Max Flow) criterion. However, rerouting that realizes the k-successively shortest link disjoint paths (KSP) may be faster, easier, and, in distributed implementation, more robust than a distributed counterpart for Max Flow. The issue is, therefore, what the restoration capacity penalty is if KSP is used instead of Max Flow. To explore this tradeoff, the authors present a comparative study of the effectiveness of KSP versus Max Flow as an alternative rerouting criteria in the context of transport network span restoration. The comparison applies to both centrally controlled and distributed restoration systems. Study methods include exhaustive span failure experiments on a range of network models, and parametric and analytical investigations for insight into the factors resulting in KSP versus Max Flow differences. The main finding is that KSP restoration capacity is more than 99.9% of that from Max Flow in typical network models. The hypothesis is made that a generalized "trap" topology is responsible for all KSP-Max Flow capacity differences. The hypothesis is tested experimentally and used to develop analytical bounds which agree well with observed results. These findings and data are relevant to standards makers and equipment developers in specifying and engineering future restorable networks. >
199 citations
NEC1
TL;DR: In order to achieve fast restoration, a distributed control mechanism that is applicable to both line and path restoration is proposed, and the shared use of spare channels for various failure scenarios, including multiple failure cases, are allowed.
Abstract: With the advent of networking technologies intelligent network elements, such as the digital cross-connect system (DCS), will make it possible to dynamically reconfigure a network for restoration purposes. Both restoration control of DCSs and spare-channel design issues are presented, and how they work together so that a fast and economical SONET self-healing network is obtained. In order to achieve fast restoration, a distributed control mechanism that is applicable to both line and path restoration is proposed. The proposed method allows the shared use of spare channels for various failure scenarios, including multiple failure cases, so that the efficient use of spare channels can be achieved. A linear-programming-based scheme is proposed to obtain spare-channel assignment, where a network-flow technique is used. Through a simulation study, a fast and economical self-healing network is verified. >
193 citations
"Optimal capacity placement for path..." refers background or methods in this paper
...Previous work used an IP approach based on -flow -cut considerations to solve the spare capacity placement problem in a span-restorable network [4], [11], [20]....
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...Issues related to the restoration mechanisms themselves are addressed in related works [1], [2], [4], [21], [27]....
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Proceedings Article•
01 Jan 1987
180 citations