Recently, Ethernet has become the dominant data-transmission technology due to its simplicity and low cost. Ethernet started as a Local Area Network (LAN) technology, but is also now used for end-to-end communications. A number of new protocols, such as Ethernet OAM, VLAN, PBB-TE, and MPLS-TP, have been developed to migrate Ethernet from a LAN technology to a Carrier Class technology.
Ethernet Operations, Administration and Maintenance (OAM) has been developed to simplify operations, administration, and maintenance of complex Ethernet networks and to reduce operational costs. Ethernet OAM supports link fault management, Connectivity fault management and performance monitoring; it is defined in IEEE 802.3 (former IEEE 802.3ah), IEEE 802.1ag and ITU-T Y.1731.
Virtual Local Area Networks (VLANs) defined in IEEE 802.1Q, divide a LAN on an organizational basis by functions, project teams, or applications. Stacked VLAN (Q-in-Q), defined in IEEE 802.1ad, is a VLAN(s) carried in a VLAN. It permits a service provider to carry customer VLAN traffic transparently through a service provider VLAN. In some cases the service provider and/or customer use more than one VLAN tag.
Provider Backbone Bridges (PBB) - Traffic Engineering (PBB-TE) was designed to provide Carrier Class Ethernet with the deterministic connection-oriented features of TDM. It achieves this by using both PBB – often called MAC-in-MAC – and VLAN technologies to identify traffic. The management system handles routing of traffic streams over the network using point-to-point connection paths and the OAM protocol. The management system also creates a backup route, supporting the ability to switchover if required.
MultiProtocol Label Switching (MPLS) - Traffic Profile (MPLS-TP) is an extension of the MPLS protocol suite and was designed to provide MPLS networks with deterministic carrier-class services. The transport profile allows connectionless traffic to be encapsulated, making it connection-oriented. MPLS-TP creates Label-Switched Paths (LSP) to transport traffic over the network, and also uses OAM information, including information like Automatic Protection Switching (APS).