Spare capacity allocation using partially disjoint paths for dual link failure protection

A shared backup path protection (SBPP) scheme can be used to protect dual link failures by pre-planning each traffic flow with mutually disjoint working and two backup paths while minimizing the network overbuild. However, many existing backbone networks are bi-connected without three fully disjoint paths between all node pairs. Hence in practice partially disjoint paths (PDP) have been used for backup paths instead of fully disjoint ones. This paper studies the minimum spare capacity allocation (SCA) problem using PDP within an optimization framework. This is an extension of the spare provision matrix (SPM) method for PDP. The integer linear programming (ILP) model is formulated and an approximation algorithm, Successive Survivable Routing (SSR), is extended and used in the numerical study. © 2013 Scientific Assoc for infocom

Heuristic for the design of fault tolerant logical topology.

Wavelength division multiplexing (WDM) in optical fiber networks is widely viewed as the savior for its potential to satisfy the huge bandwidth requirement of network users. Optical cross connect (OCX) in WDM network facilitates the switching of signal on any wavelength from any input port to any output port. As a result, it is possible to establish ligthpaths between any pair of nodes. The set of lightpaths established over fiber links defines logical topology. In our thesis, we proposed a heuristic approach for the design of fault tolerant logical topology. Our design approach generalizes the design protection concept and enforces wavelength continuity constraint in a multi-hop optical network. In our work, we first designed logical topology for fault free state of the network. We, then, added additional lightpaths for each single link failure scenario. Numerical results clearly show that our approach outperforms Shared path protection and Dedicated path protection. Our simulation result shows that our approach is feasible for large networks. (Abstract shortened by UMI.) Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .S24. Source: Masters Abstracts International, Volume: 44-03, page: 1413. Thesis (M.Sc.)--University of Windsor (Canada), 2005

Survivable Cloud Network Mapping for Disaster Recovery Support

Network virtualization is a key provision for improving the scalability and reliability of cloud computing services. In recent years, various mapping schemes have been developed to reserve VN resources over substrate networks. However, many cloud providers are very concerned about improving service reliability under catastrophic disaster conditions yielding multiple system failures. To address this challenge, this work presents a novel failure region-disjoint VN mapping scheme to improve VN mapping survivability. The problem is first formulated as a mixed integer linear programming problem and then two heuristic solutions are proposed to compute a pair of failure region-disjoint VN mappings. The solution also takes into account mapping costs and load balancing concerns to help improve resource efficiencies. The schemes are then analyzed in detail for a variety of networks and their overall performances compared to some existing survivable VN mapping scheme

Dual-failure Survivability for Multi Quality Data using Single p-cycle

Dual-failure scenarios are a real possibility in today’s optical networks and it is becoming more and more important foe carriers and network operators to consider them when designing their networks. p-Cycle is a recent approach in optical network protection. p-Cycle use preconnected cycles of spare capacity to restore affected working traffic. We propose new method and strategies to support multiple qualities of service classes in a static pcycle based network Design, using the same global set of resources as required to operate a network with only a single failure protected service class. A propose new method to provide dual failures survivability using p-cycle. A p-cycle is set up for each link. When link is failure, the system will on-line select the best route of pcycle to react. In single failure or dual failure, data does not divert randomly in route of p-cycle. Data packets are switched based on priority criteria it means that the higher priority packets go through shortest distance route of pcycle and lowest priority data packets go through longest distance route of p-cycle

Disjoint path protection in multi-hop wireless networks with interference constraints

We consider the problem of providing protection against failures in wireless networks by using disjoint paths. Disjoint path routing is commonly used in wired networks for protection, but due to the interference between transmitting nodes in a wireless setting, this approach has not been previously examined for wireless networks. In this paper, we develop a non-disruptive and resource-efficient disjoint path scheme that guarantees protection in wireless networks by utilizing capacity "recapturing" after a failure. Using our scheme, protection can oftentimes be provided for all demands using no additional resources beyond what was required without any protection. We show that the problem of disjoint path protection in wireless networks is not only NP-hard, but in fact remains NP-hard to approximate. We provide an ILP formulation to find an optimal solution, and develop corresponding time-efficient algorithms. Our approach utilizes 87% less protection resources on average than the traditional disjoint path routing scheme. For the case of 2-hop interference, which corresponds to the IEEE 802.11 standard, our protection scheme requires only 8% more resources on average than providing no protection whatsoever.National Science Foundation (U.S.) (CNS-1116209)National Science Foundation (U.S.) (CNS-1017800)United States. Defense Threat Reduction Agency (HDTRA-09-1-005