Advances in DWDM Optical Networking Technology

transport network upgrading because of its potential cost-effectiveness, large capacity, flexible reconfiguration and strong survivability, it has been flourished all over the world. Many achievements in this field have been obtained due to the hard work of the related engineers all over the world. The implement and thriving of commercial Optical Internet is just a problem of time. In 1998, a four-node all-optical metropolitan self-healing ring testbed called SHAONet (Shanghai All-Optical Network testbed) have been established in Shanghai Jiao Tong University for the first time in China. It brought about the development of optical networking technology in china, and the achievement has shorted the gap between China and advanced countries in the field of optical networking technologies. Key words: DWDM optical networks, OADM, OXC, IP/DWDM, all-optical metropolitan self-healing ring Today, with the exploding of Internet, Intranet and e-commerce applications, every major service provider worldwide is facing the formidable bandwidth challenge of designing or evolving their core network architectures. The development of current telecommunication service needs broadband optical transport networks with cost-effectiveness, large capacity, high flexibility an