Performance Estimation of Overlaid Lightpath Networks for Lambda Users

In future, lightpaths will be dynamically provided to users by the use of GMPLS but lightpath networks may be overlaid to the users. When the users want to find idle wavelengths by probing for lightpath provisioning, they may not be able to obtain information about all the idle wavelengths along the route in the overlaid lightpath network. They are only allowed to include a limited number of wavelengths for probing. In order to avoid wavelength contention and reduce blocking probability, we present a method for performance estimation of overlaid lightpath networks from a user side. In this method, we try to find wavelengths that are likely to be idle. This is done by the wavelength- based rank accounting for each pair of a source and a destination. Rank is calculated each time a lightpath is provisioned at a pair regardless of the success or failure of the provisioning. We demonstrate that the method of estimation is effective through simulation experiments and also present an initial implementation of a lightpath-provisioning system that uses our performance estimation method based on the GMPLS RSVP-TE mechanism.