Rapid Recovery from Link Failures in Software-Defined Networks

S. M. Raza, Dongsoo S. Kim,  Hyunseung Choo




Carrier-grade networks (CGNs) can leverage the network programmability of software-defined networking (SDN) to ensure fast recovery and high availability. However, for the successful adoption of SDN, the failure recovery requirement must be addressed. Local detouring is a popular approach for faster recovery rather than path-based end-to-end recovery. For fast local recovery, alternate paths must be preinstalled for each individual flow on the link, which in some cases results in storing thousands of alternate path flow rules. Furthermore, the dependence on the controller for dynamic per-flow detouring may delay the recovery. In this paper, we propose local immediate (LIm) and immediate controller dependent (ICoD) recovery mechanisms to address the limitations of OpenFlow-based link recovery approaches. Our proposed mechanisms considerably reduce the alternate path flow rules by aggregating the disrupted flows using virtual local area network (VLAN) tagging. The proposed algorithms achieve recovery within 3 ms and 20 ms, respectively and satisfy the strict 50 ms recovery requirement of CGNs. LIm and ICoD also reduce the alternate path flow storage requirement by up to 99%. Simulation results reveal that the flow-aggregation also reduces the effort of the controller and minimizes the alternate path installation traffic.


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