Link-state update policies for all-optical DWDM transport networks

It has been demonstrated that advertising the availability of wavelength and converter resources in all-optical DWDM transport networks with sparse wavelength conversion capabilities can drastically improve the blocking performance of these networks thus achieving better usage of the network resources. An important aspect with consequences in network performance is when to originate the wavelength-availability and converter-availability link state advertisements (LSAs). Frequent link-state advertisements could overwhelm the network control plane with many update messages that need to be processed. On the other hand, delaying these advertisements could result in inaccurate link-state information thus degrading the network blocking performance. In this paper, we propose two different link-state update policies to advertise the availability of wavelength and converter resource in all-optical DWDM transport networks with sparse wavelength conversion capabilities. The first one is very simple and serves as our base policy for comparison. The second policy, which is very efficient in handling the dynamic nature of all-optical DWDM networks with different degrees of wavelength conversion, reduces the number of LSAs considerably while maintaining the call blocking probability.