This document generalises the applicability of the pseudowire Associated Channel Header (ACH), enabling the realization of a control channel associated to MPLS Label Switched Paths (LSP), MPLS pseudowires (PW) and MPLS Sections. In order to identify the presence of this G-ACH, this document also assigns of one of the reserved MPLS label values to the 'Generic Alert Label (GAL)', to be used as a label based exception mechanism.