Analysis and algorithms for partial protection in mesh networks

This paper develops a mesh network protection scheme that guarantees a quantifiable minimum grade of service upon a failure within a network. The scheme guarantees that a fraction q of each demand remains after any single link failure. A linear program is developed to find the minimum-cost capacity allocation to meet both demand and protection requirements. For q ≤ 1/2, an exact algorithmic solution for the optimal routing and allocation is developed using multiple shortest paths. For q >; 1/2, a heuristic algorithm based on disjoint path routing is developed that performs, on average, within 1.4% of optimal, and runs four orders of magnitude faster than the minimum-cost solution achieved via the linear program. Moreover, the partial protection strategies developed achieve reductions of up to 82% over traditional full protection schemes.National Science Foundation (U.S.) (NSF grant CNS-0626781)National Science Foundation (U.S.) (NSF grant CNS-0830961)United States. Defense Threat Reduction Agency (grant HDTRA1-07-1-0004)United States. Defense Threat Reduction Agency (grant HDTRA-09-1-005)United States. Air Force (Air Force contract #FA8721-05-C-0002

Survivable mesh-network design & optimization to support multiple QoP service classes

Every second, vast amounts of data are transferred over communication systems around the world, and as a result, the demands on optical infrastructures are extending beyond the traditional, ring-based architecture. The range of content and services available from the Internet is increasing, and network operations are constantly under pressure to expand their optical networks in order to keep pace with the ever increasing demand for higher speed and more reliable links

Survivable network design with stepwise incremental cost function

Modern society has become more and more dependent on information services, transferred in both public and private network, than ever before. The use of integration of computers with telecommunications has created a so-called “Information Age”. The advent of high capacity digital telecommunication facilities has made it possible for the huge amount of traffic to be carried in an economical and efficient method, in recent years. These facilities, which are used to carry much higher capacities than the traditional ones, also result in the network’s vulnerability to the failure of network facilities, i.e. a single link failure. This thesis is concerned with the technology by which the spare capacity on the link of mesh networks is placed in order to protect the active traffic from network failure with a minimal cost. Although there have been many works to address the issue all of these works have been developed based on the assumption that the link cost with its capacity is linear. In fact, the linear cost functions does not reflect the reality that optic fiber cables with the specific amount of capacities are only available, in other words, the link cost function is stepwise rather than linear. Therefore, all existing algorithms developed for the linear assumption may not be applicable properly for the stepwise case. A novel heuristic algorithm is proposed to solve the problem in this thesis. The algorithm is composed of two parts as follows. In part one, a maximum flow algorithm is employed to work out the maximal amount of feasible spare paths consisting of spare capacities in the network to re-route the disrupted traffic at the event of network failure. In part two, a newly proposed algorithm is used to find an alternative path on which to place the non-rerouted traffic on the failed link with the minimum network cost increment. The superiority of the algorithm is presented over other algorithms published in this area

On Signaling-Free Failure Dependent Restoration in All-Optical Mesh Networks

Failure dependent protection (FDP) is known to achieve optimal capacity efficiency among all types of protection, at the expense of longer recovery time and more complicated signaling overhead. This particularly hinders the usage of FDP in all-optical mesh networks. As a remedy, the paper investigates a new restoration framework that enables all-optical fault management and device configuration via state-of-the-art failure localization techniques, such that the FDP restoration process. It can be implemented without relying on any control plane signaling. With the proposed restoration framework, a novel spare capacity allocation problem is defined, and is further analyzed on circulant topologies for any single link failure, aiming to gain a solid understanding of the problem. By allowing reuse of monitoring resources for restoration capacity, we are particularly interested in the monitoring resource hidden property where less or even no monitoring resources are consumed as more working traffic is in place. To deal with general topologies, we introduce a novel heuristic approach to the proposed spare capacity allocation problem, which comprises a generic FDP survivable routing scheme followed by a novel monitoring resource allocation method. Extensive simulation is conducted to examine the proposed scheme and verify the proposed restoration framework

Logical topology design for IP rerouting: ASONs versus static OTNs

IP-based backbone networks are gradually moving to a network model consisting of high-speed routers that are flexibly interconnected by a mesh of light paths set up by an optical transport network that consists of wavelength division multiplexing (WDM) links and optical cross-connects. In such a model, the generalized MPLS protocol suite could provide the IP centric control plane component that will be used to deliver rapid and dynamic circuit provisioning of end-to-end optical light paths between the routers. This is called an automatic switched optical (transport) network (ASON). An ASON enables reconfiguration of the logical IP topology by setting up and tearing down light paths. This allows to up- or downgrade link capacities during a router failure to the capacities needed by the new routing of the affected traffic. Such survivability against (single) IP router failures is cost-effective, as capacity to the IP layer can be provided flexibly when necessary. We present and investigate a logical topology optimization problem that minimizes the total amount or cost of the needed resources (interfaces, wavelengths, WDM line-systems, amplifiers, etc.) in both the IP and the optical layer. A novel optimization aspect in this problem is the possibility, as a result of the ASON, to reuse the physical resources (like interface cards and WDM line-systems) over the different network states (the failure-free and all the router failure scenarios). We devised a simple optimization strategy to investigate the cost of the ASON approach and compare it with other schemes that survive single router failures

Survivable network design of all-optical network.

Kwok-Shing Ho.Thesis (M.Phil.)--Chinese University of Hong Kong, 2002.Includes bibliographical references (leaves 69-71).Abstracts in English and Chinese.List of Figures --- p.viList of Tables --- p.viiChapter Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Overview --- p.1Chapter 1.2 --- Thesis Objectives --- p.6Chapter 1.3 --- Outline of Thesis --- p.8Chapter Chapter 2 --- The Spare Capacity Planning Problem --- p.9Chapter 2.1 --- Mathematical Model of the Spare Capacity Planning Problem --- p.12Chapter 2.1.1 --- Variable Definitions --- p.12Chapter 2.1.2 --- Objective Function and Constraints --- p.15Chapter 2.1.3 --- Complexity --- p.17Chapter 2.2 --- Greedy Algorithm - Spare Capacity Allocation and Planning Estimator (SCAPE) --- p.19Chapter 2.2.1 --- Working Principle of SCAPE --- p.20Chapter 2.2.2 --- Implementation of SCAPE --- p.22Chapter 2.2.3 --- Improved SCAPE --- p.23Chapter 2.3 --- Experimental Results and Discussion --- p.27Chapter 2.3.1 --- Experimental Platform --- p.27Chapter 2.3.2 --- Experiment about Accuracy of SCAPE --- p.27Chapter 2.3.3 --- Experiment about Minimization of Network Spare Capacity --- p.30Chapter 2.3.4 --- Experiment about Minimization of Network Spare Cost --- p.35Chapter 2.4 --- Conclusions --- p.38Chapter Chapter 3 --- Survivable All-Optical Network Design Problem --- p.39Chapter 3.1 --- Mathematical Model of the Survivable Network Design Problem --- p.42Chapter 3.2 --- Optimization Algorithms for Survivable Network Design Problem --- p.44Chapter 3.2.1 --- Modified Drop Algorithm (MDA) --- p.45Chapter 3.2.1.1 --- Drop Algorithm Introduction --- p.45Chapter 3.2.1.2 --- Network Design with MDA --- p.45Chapter 3.2.2 --- Genetic Algorithm --- p.47Chapter 3.2.2.1 --- Genetic Algorithm Introduction --- p.47Chapter 3.2.2.2 --- Network Design with GA --- p.48Chapter 3.2.3 --- Complexity of MDA and GA --- p.51Chapter 3.3 --- Experimental Results and Discussion --- p.52Chapter 3.3.1 --- Experimental Platform --- p.52Chapter 3.3.2 --- Experiment about Accuracy of MDA and GA --- p.52Chapter 3.3.3 --- Experiment about Principle of Survivable Network Design --- p.55Chapter 3.3.4 --- Experiment about Performance of MDA and GA --- p.58Chapter 3.4 --- Conclusions --- p.62Chapter Chapter 4 --- Conclusions and Future Work --- p.63Appendix A The Interference Heuristic for the path restoration scheme --- p.66Bibliography --- p.69Publications --- p.7