Subarea PU not active, or invalid virtual route: A session-activation request for a peripheral PU or LU cannot be satisfied because there is no active SSCP-PU session for the subarea node providing boundary function support, or the virtual route for the specified SSCP-PU (Type 1 or Type 2 nodes) or SSCP-LU session is not the same as that used for the SSCP-PU session of the Type 1 or Type 2 node’s PU or the LU’s subarea PU.