Design and Performance Evaluation of a Separated Control Signaling Protocol for WDM Optical Networks

In WDM optical networks, an efficient control signaling protocol is required to dynamically establish lightpaths. This paper proposes a separated control signaling protocol (SCSP) and compares the performance of SCSP with a conventional integrated control signaling protocol (ICSP). The conventional ICSP makes reservations sequentially from the source to the destination for setting up and tearing down lightpaths. It increases the control overhead and wastes the network resource if it cannot reserve the network resource at an intermediate node. Specifically, if the receiver at the destination is not available after successful reservation at intermediate nodes, it wastes a lot of bandwidth. It causes decreasing chances of reservation for other lightpaths. Instead, SCSP separates bearer control from call control to reduce the waste of network resources. The call control function checks the availability of network resources such as wavelengths and receivers. Bearer control reserves, allocates, and releases network resources. To evaluate the performance of the two protocols, they are mathematically analyzed using a probabilistic model. Simulation results are also provided to compare the proposed protocol with the conventional ICSP in terms of utilization and blocking probability. From the results of simulation and iterative analysis, we can observe that SCSP performs better than ICSP.