Optimizing IGP Link Costs for Improving IP-level Resilience

Recently, major vendors have introduced new router platforms to the market that support fast IP-level failure pro- tection out of the box. The implementations are based on the IP Fast ReRoute–Loop Free Alternates (LFA) standard. LFA is simple, unobtrusive, and easily deployable. This simplicity, however, comes at a severe price, in that LFA usually cannot protect all possible failure scenarios. In this paper, we give new graph theoretical tools for analyzing LFA failure case coverage and we seek ways for improvement. In particular, we investigate how to optimize IGP link costs to maximize the number of protected failure scenarios, we show that this problem is NP- complete even in a very restricted formulation, and we give exact and approximate algorithms to solve it. Our simulation studies show that a deliberate selection of IGP costs can bring many networks close to complete LFA-based protection

A survey of strategies for communication networks to protect against large-scale natural disasters

Recent natural disasters have revealed that emergency networks presently cannot disseminate the necessary disaster information, making it difficult to deploy and coordinate relief operations. These disasters have reinforced the knowledge that telecommunication networks constitute a critical infrastructure of our society, and the urgency in establishing protection mechanisms against disaster-based disruptions

Linear Formulation for Segment Shared Protection

This paper proposes a novel linear formulation for the problem of segment shared protection, where the switching/merging nodes and the least-cost link-disjoint working and protection segments corresponding to each switching/merging node-pair are jointly determined for a connection request. A novel approach of arc-reversal graph transformation is introduced. We verify the ILP and compare it with three reported approaches for solving the segment shared protection problem, namely CDR, PROMISE, and OPDA, by launching dynamic connection requests on two network topologies. From the experiment results, we observe that the ILP can always yield better results in terms of the total cost taken by the working and protection segments. We conclude that the proposed ILP formulation is a step ahead of the most state-of-the-art techniques in solving the shared protection problem, which provides a means of evaluating any other segment shared protection algorithms

Improving Resiliency and Throughput of Transport Networks with OpenFlow and Multipath TCP: Demonstration of Results Over the Géant OpenFlow testbed

Currently, each networking layer redundantly has its own recovery mechanism resulting in more expensive networking equipment and higher operational costs. Can we get rid of all these mechanisms below the transport layer and use multipath transport protocol to provide the required resiliency