The ForwardingRelationshipEncapsulation (FRE) is bounded by two or more endpoints each of which may be associated with a TPEs. The FRE represents the enabled constrained potential for forwarding of information between those endpoints (i.e. to/from the associated TPEs) for a particular layer protocol (where the TPE must clearly have LayerTerminations (LTs) associated that operate with that layer protocol). Note that where the TPE is associated indirectly with a TopologicalLink (TL) the information from the FRE will be passed across the network via that TL and where the LT of the TPE is a layer protocol termination the information from the FRE will be prepared to transition layers of the network.<br/><br/><br/><br/>Each endpoint of the FRE has a specific role in the context of the FRE where the possible roles and the interpretation of the roles are goverened by the type of FRE. The types of FRE are equivalent to the types of SNC described in MTOSI SD1-36 (refer to SD1-36_SNCTypes for explanation of SNC Properties, SNC Parameters, unidirectional SNCs, Point-to-Multipoint SNC, Routing Constraints and Route Discovery).<br/><br/><br/><br/>An FRE may encompass a sequence of supporting FREs (which describe in more detail the route of the information comveyed by the FRE thorugh the network). The relationship is recursive such that a supporting FREs may itself be supported FREs (i.e. FREs supporting FREs supporting FREs). The FRE at the highest level of a recursion is referred to as top-level FRE. Note that a Call may have one or more parallel top-level Connection(s).<br/><br/><br/><br/>An FRE may be used to represent various planning states. In these planning states the FRE may have only partial values for associated TPE name etc.<br/>