Design of mixed MPLS/OSPF routing in IP networks

In English In this paper we address the problem of Internet networks optimization using a mixed Open Shortest Path First (OSPF) and Multi Protocol Label Switching (MPLS) routing. Since MPLS can be combined with any routing protocol there appeared an idea of coupling IP streams routed via OSPF protocol and MPLS Label Switched Paths (LSPs) in the same network. One expected advantage behind such a combined routing is to simplify the design stage by allowing some flows to be routed via OSPF while the others are transmitted via MPLS LSPs. In the paper we discuss two routing optimization problems. In the first case, OSPF routing protocol works over logical network with generalized IP links. These links are either standard IP links or IP links established as MPLS LSPs. In the second case we distinguish two types of demands depending on whether OSPF routing is used or packets are switched by MPLS Label Switch Routers (LSR). We present here both problem formulations and discuss the issue on how to effectively solve these problems.