Issues on routing in multi-layer and multi-domain optical networks

Routing in multi-layer and multi-domain optical networks is now getting more and more complicated. Path Computation Element (PCE) is proposed to resolve this problem for its advantage to compute a path with overall situations. There are several issues on PCE-based routing architecture in multi layer and multi-domain scenarios, such as multi-layer traffic grooming optimization, physical impairment aware routing across domains and physical impairment information advertisement. In this paper PCE-based traffic grooming strategy in control plane, IA-BRPC routing procedure and a physical impairment processing approach to improve the efficiency of advertisement are discussed respectively.