carrier Ethernet transport (CET)
Carrier Ethernet Transport (CET) is a concept for building scalable transport infrastructures that support the evolution to Next Generation Networks( NGN). Carrier Ethernet includes gateway functions and wavelength division multiplexing(WDM) tunneling with wavelength switching and sub-wavelength switching capabilities.
In Carrier Ethernet Transport, Ethernet as a cost-effective and reliable technology is combined with the performance of wavelength division multiplexing to form a scalable transport technology that forms a convergence with optical transmission networks. In this technology, connections rather than data packets are switched. To this end, the previous separation of the aggregation layer in conjunction withIP/ MPLS and the optical domain is replaced by a converged optical Ethernet layer. This leads to a simplified transport architecture in metro networks built on a wavelength platform based on an optical transport network( OTN) and Ethernet.
The switching function can be implemented at three different levels: Wavelength switching, sub-wavelength switching with Gigabit Ethernet, and Ethernet tunneling. The different switching components provide the corresponding connections into the core network and to the service layer.