optical crossconnect (OTH) (OXC)
Optical Cross Connects (OXC) are optical switches used in optical and core networks to act as non-blocking switching systems between any(STM)interfaces.
An optical cross-connect is a functional unit consisting of an optical switch, a wavelength switch, and a wavelength converter. It can switch incoming optical fibers to any outgoing fiber; in this case, it works as an optical space switch. It can switch individual wavelengths from an incoming fiber to any outgoing fiber as a wavelength selective switch(WSS), which is equivalent to the function of wavelength division multiplexing, and in addition, an OXC can convert wavelengths and place them on an outgoing fiber. OXC technology can be used to build optical networks in meshed structures.
An optical cross connect, also known as fiber cross connect (FXC) or wavelength cross connect ( WXC), works with wavelengths (`lambda`). Here, an optical path corresponds to a Label Switched Path ( LSP) signaled by Multi-Protocol Label Switching ( MPLS) traffic engineering.
An optical cross connect consists of two components: the control component and the forwarding component. The control component controls traffic flow, finds resources in the optical network such as free wavelengths, collects topology and state information, handles path selection and link management in the optical network, and provides resilience.
The forwarding component is controlled by building switching tables in the cross-connect. These include the incoming interface, the incoming wavelength, and the outgoing interface and wavelength.