Routing and admission control issues for LSPs in MPLS networks

Increasing demand for multimedia and distributed applications in recent years has drawn renewed attention to Quality of Services (QoS) routing in IP/MPLS network. This paper presents several new algorithms to be implemented for that purpose. We look, in a first part of the problem at organizing the mapping of Label Switching Paths (LSPs) throughout the network such that we can compromise between several Traffic Engineering (TE) objectives: load balancing, avoiding network bottlenecks, reducing routing cost and minimizing path hop count. In the second part, to bring more and more QoS guarantees to high speed multimedia applications, we have introduced Differentiated Services. In this issue, we propose a new admission control mechanisms based on bandwidth resources. Preemption has been recognized as an important paradigm in our research and it has been conducted into two dimensions: preemption inter Class Type (CT) and preemption across a CT. To achieve significant performance improvement for preemption treatment, we propose two different algorithms: a bandwidth preemption algorithm which selects amount of bandwidth to preempt and an LSPs preemption algorithm which selects the most appropriate LSPs to preempt on the basis on several optimization criteria to avoid rerouting explosion. Simulations studies have been carried out to compare the performance of our approach against existing ones.