The current thinking about IP over WDM by outlining a path to optical data networking, that includes multiple data networking protocol coupled with a protocol-neutral optical networking infrastructure is challenged. This tutorial discusse. The current thinking about IP over WDM by outlining a path to optical data networking, that includes multiple data networking protocol coupled with a protocol-neutral optical networking infrastructure is challenged. This tutorial discusses the diversity of data networking protocols and network architectures for optical data networking. The bandwidt. Today's TDM-based transport networks have been designed to provide an assured level of performance and reliability for the predominant voice and based-line services. Proven technologies, such as SDH, have been widely deployed, providing high-capacity transport, scalable to gigabit per second rates, for voice and leased-line applications. SDH self-. IP over WDM, as defined today, imposes a restrictive view of the capabilities that data networks and optical networks can provide. The constraints, introduced by a single protocol stack and not by fully using the networking capabilities at the optical layer are very restrictive for some network applications. The networking trends mentioned above re. Telecommunications traffic continues to grow at a very fast pace. This is accelerated through the increasing volume of data and mobile traffic, especially in India, through the recent liberalization of the telecommunications market. A solution can be adopted to meet the ever-increasing traffic requirements based on a combination of WDM, SDH, and IP. WDM is a technology that enables various optical signals to be transmitted by a single fiber. Its principle is essentially the same as Frequency Division Multiplexing (FDM). That is, several signals are transmitted using different carriers, occupying non-overlapping parts of a frequency spectrum. In case of WDM, the spectrum band used is in the reg.