Optical Network Control: Architecture, Protocols, and Standards

10.3. Routing with Physical Diversity

Route diversity is an important constraint often imposed on multiple connections between the same end points in an optical network. In particular, the requirement on link diversity is common, that is, two connections may not be routed over a common link. Occasionally, a more stringent node diversity requirement might arise, that is, two connections may not be routed via any common node.

Physical diversity between connections is driven by the need to prevent connections from being affected by the same failure. Two connections are said to be diverse if no single failure would affect both of them. In traditional transport networks, the dominant failure mode is a failure in the interoffice plant, such as a fiber ...