sentences:  Additionally Ethernet is being reinforced with operations, administration, and maintenance (OAM) capabilities through the work of various standard bodies (IEEE 802.1ag, ITU-T Y.1731 and G.8021, IEEE 802.3ah).PBT/PBB equipment leverages economies of scale inherent in Ethernet, promising about 30%–40% cheaper solutions compared to T-MPLS equipment with identical features and capabilities, making PBT a better overall return on investment.T-MPLS, as its name implies, is a derivative of MPLS that renounces all MPLS signaling features and, like PBT, uses a centralized control-plane to perform routing and traffic engineering.