Integrated dynamic shared protection algorithm for GMPLS networks

The path protection approach is widely investigated as a survivability solution for GMPLS networks, which has the advantage of efficient capacity utilization. However, there is a problem of the path protection approach that searching a disjoint backup path for a primary path is often unsuccessful. In order to resolve this problem, an integrated dynamic shared protection （IDSP） algorithm is proposed. The main idea of the proposed algorithm is that the path protection approach is first used to establish a backup path for the primary path; if the establishment is unsuccessful, then the primary path is dynamically divided into segments whose hop count are not fixed but not more than the limitation calculated by the equations introduced. In this proposal, backup bandwidth sharing is allowed to improve the capacity utilization ratio, which makes the link cost function quite different from previous ones. Simulation experiments are presented to demonstrate the efficiency of the proposed method compared with previous methods. Numerical results show that IDSP can not only achieve low protection failure probability but can also gain a better tradeoff between the protection overbuild and the average recovery time.

Pervasive Dependability in Wireless Cloud Networking: a BlueGreen Topological Control Approach

The future Wireless Cloud Networks (WCNs) are required to satisfy both extremely high levels of service resilience and security assurance (i.e., Blue criteria) by overproviding backup network resources and cryptographic protection on wireless communication respectively, as well as minimizing energy consumption (i.e., Green criteria) by switching off unnecessary resources as much as possible. There is a contradiction to satisfy both Blue and Green design criteria simultaneously. In this paper, we propose a new BlueGreen topological control scheme to leverage the wireless link connectivity for WCNs using an adaptive encryption key allocation mechanism, named as Shared Backup Path Keys (SBPK). The BlueGreen SBPK can take into account the network dependable requirements such as service resilience, security assurance and energy efficiency as a whole, so as trading off between them to find an optimal solution. Actually, this challenging problem can be modeled as a global optimization problem, where the network working and backup elements such as nodes, links, encryption keys and their energy consumption are considered as a resource, and their utilization should be minimized. The case studies confirm that there is a trade-off optimal solution between the capacity efficiency and energy efficiency to achieve the dependable WCNs.

Efficient Routing Protection Algorithm Based on Optimized Network Topology

Network failures are unavoidable and occur frequently.When the network fails,intra-domain routing protocols deploying on the Internet need to undergo a long convergence process.During this period,a large number of messages are discarded,which results in a decline in the user experience and severely affects the quality of service of Internet Service Providers(ISP).Therefore,improving the availability of intra-domain routing is a trending research question to be solved.Industry usually employs routing protection algorithms to improve intra-domain routing availability.However,existing routing protection schemes compute as many backup paths as possible to reduce message loss due to network failures,which increases the cost of the network and impedes the methods deployed in practice.To address the issues,this study proposes an efficient routing protection algorithm based on optimized network topology(ERPBONT).ERPBONT adopts the optimized network topology to calculate a backup path with the minimum path coincidence degree with the shortest path for all source purposes.Firstly,the backup path with the minimum path coincidence with the shortest path is described as an integer programming problem.Then the simulated annealing algorithm ERPBONT is used to find the optimal solution.Finally,the algorithm is tested on the simulated topology and the real topology.The experimental results show that ERPBONT effectively reduces the path coincidence between the shortest path and the backup path,and significantly improves the routing availability.

Fast network restoration with equivalent cooperative routing

Aiming at the problem of failure recovery in current networks,a fast failure recovery method based on equivalent cooperative routing is proposed.Firstly,the transmission path between the source and destination nodes is divided into several non-overlapping path segments.Next,backup paths are deployed for each link in the path segment through segmented routing technology,which ensures fast routing recovery after failure.Additionally,in order to avoid damaging the QoS of the data stream through the failure recovery process,the transmission is guaranteed by the intersegment QoS complement.The experimental results show that the proposed method has a low failure recovery delay under a relatively small flow table cost.