TopologicalLink, DropSideTopologicalLink, BBTopologicalLink, and BBDropSideTopologicalLink objects may be part of a TopologicalLinkGroup, as indicated by the ComposedOf relationship. A TopologicalLinkGroup represents a group of topological links that together provide protection capabilities. For example, a TopologicalLink may be part of a 1+1 protection group, or part of a 2F-BLSR ring, etc.

The uses of TopologicalLinkGroup objects are discussed in more detail in “Protection Schemes” on page 95.