Hop constraint based admission and fairness control in IP-over-WDM networks

From both user and operator perspectives, fairness is an important aspect in IP-over-WDM networks where Label Switched Paths (LSPs) are dynamically groomed over optical networks. The setup of LSPs with long distances experiences a higher blocking probability due to both lightpath establishment unfairness in the optical layer and link cascading effect in the IP/MPLS layer. A simple LSP connection admission and fairness control mechanism is proposed in this article. This control mechanism is based on hop constraint, in which an LSP is accepted with a pre-assigned probability according to its distance and the hops of its route. Through suppressing connection of short-distance LSPs that overuse bandwidth to facilitate the setup of LSPs with long distances, this proposal achieves fine distance fairness performance with a slight overall blocking probability increment.