Optical-label-based all-optical packet switching routers

Current developments in optical components technologies enable wavelengths to be very narrowly spaced, transforming the optical fiber into a multi-terabit capacity medium. A new generation of "all-optical" cross-connects started to appear in the market leading to a number of advantages such as increased switching capacity, decreased overall network costs, scalability and transparency resulting in the capability to support any protocol. An additional advantage is the ability to configure the switching fabric and the wavelength converters in real-time. All-optical switches are made possible by a number of technologies that allow the managing and switching photonic signals without converting them into electronic signals. Only a couple of technologies appear ready to make the transition form the laboratory to the network, where they must support the basic feature set of a carrier-grade, scalable optical switches. Arguably, the leading technology for developing an economically viable, scalable all-optical , OOO switch is the 3D micro-electromechanical system (MEMS). 3D MEMS uses control mechanisms to tilt mirrors in multiple directions (3 dimensional). For the control of optical cross-connects, the MP Lambdas approach was proposed by IETF, according to which the MPLS traffic engineering control plane is used in optical cross connects. In this paper, evolution of architectures for optical cross-connects all optical switch are discussed with different switch fabrics such as micro-electro-mechanical all optical switch fabric and arrayed-wavelength-grating routers (AWGRs). The paper includes also an illustration of the major function of the multi protocol label switching MPLS optical router and the use of MP lambda switch to control the all optical switch.