Optical Path Protection with Fast Extra Path Preemption

Abstract

Emerging GMPLS (Generalized Multi-Protocol Label Switching)-based photonic networks are expected to realize the dynamic allocation of network resources for a wide range of applications, such as carriers' backbone networks as well as enterprise core networks and GRID computing. To address diverse reliability requirements corresponding to different application needs, photonic networks have to support various optical path recovery schemes. Thus GMPLS standardization bodies have developed failure recovery protocols for 1+1 protection, 1:N protection and restoration, with support of extra traffic and shared use of back-up resources. Whereas the standardization efforts cover a full spectrum of recovery schemes, there have not been many reports on actual implementations of such functionalities, and none of them included extra traffic. This paper introduces an OXC (Optical Cross Connect) implementation of GMPLS's failure recovery functionalities supporting 1+1 protection, M:N protection and extra path. Here extra path is an extension of GMPLS protection's extra traffic which can partially reuse protected paths' back-up resources. Evaluation of the implementation confirms rapid recovery of protected traffic upon a failure, even when preemption of an extra path is involved. It is also shown that its preemption scheme can resolve the issue of the poor scalability of GMPLS-based preemption when multiple extra paths are pre-empted upon a failure.