Transport-SDN application to dynamically optimize deployed optical transport networks

Evolution from todays statically operated wavelength division multiplex (WDM) networks towards future transport software defined networking (T-SDN) controlled flexible networks is in progress, enabling both an easier network set-up as well as network operation. To support this flexible approach autonomous optimization of network resources especially within deployed large WDM networks would be beneficial. Our network optimization is designed to act as an independent application on top of an SDN-controller. After the detection of non-optimized wavelengths, e.g. wavelengths meandering across the network, it performs a rerouting of wavelength channels taking into account different optimization metrics in order to reroute only one ore a few wavelength(s) per iteration. This is especially important in optical networks due to the analog behavior of optical signals within non-linear fibers which cause a strong interaction between wavelengths travelling the same link. So, only very few changes (e.g. by rerouting) can be performed to limit the annoyance of all other wavelengths along the link. We have developed and implemented a new incremental method for continuous network optimization running in the background as an application to overcome this problem.