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With network virtualization more and more popular, how to protect the virtual networks (VNs) from a single substrate link failure is increasingly important. Existing protection schemes like dedicated backup and shared backup, suffer from high resource cost and delayed recovery, respectively. To offer instantaneous recovery with less redundant resource, in this paper, we propose a coding-aware VN mapping framework which applies network coding on the VN protection for the first time. This algorithm framework includes two network coding mechanisms with their corresponding link mapping algorithms. The simple coding mechanism is resource-efficient and suitable for high nodal degree network. The general coding mechanism relaxes two restrictions in simple coding, and is so flexible to make more VNs be mapped successfully. The simulation experiments show that our proposed algorithms can significantly improve the request acceptance ratio and revenue to cost ratio, while reducing the backup bandwidth gain of VNs.

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It is well known that today's inter-domain routing protocol, Border Gateway Protocol (BGP), converges slowly during network failures. Due to the distribution nature of Internet routing decisions and the rate-limiting timer Minimum Route Advertisement Interval (MRAI) of BGP, unavoidable convergence latency is introduced in reaction to network changes. During the period of convergence temporarily routing table inconsistencies cause short-term routing blackholes and loops which result in widespread temporary burst packet loss. In this paper, we present ROute-Free Forwarding (ROFF) -a novel technique for packet delivering continuously during periods of convergence. With slightly modifications on IP packet header and BGP, route loops and blackholes can be avoided. Our preliminary evaluation demonstrates that ROFF succeeds in reducing the number of Autonomous Systems (ASes) which experience burst packet loss and the duration of packet loss.

No abstract