Class of service with Partial Protection in multilayered networks with SRLG constraints

This paper presents a novel shared mesh restoration scheme for survivable multilayered networks with Shared Risk Link Groups (SRLG) considerations. We develop a heuristic restoration scheme called Two-Step Partial Protection Risk Algorithm to tackle three major problems: (1) network survivability (2) optimization of spare bandwidth, and (3) offering differentiated classes of service. The proposed algorithm provides partial SRLG-diversity for ‘high-risk’ SRLGs that fail the user-specified availability criteria. A linear program formulation is also derived to minimize the backup bandwidth capacity under flow and link-diversity constraints. We show that fewer demands are disrupted in a SRLG-protected network compared to link-only protection, and the number of blocked demands as well as the disrupted demands depend on the number and length of SRLGs in the network.