On the design of MPLS-ASON/GMPLS interconnection mechanisms

In this paper we propose a mechanism for connecting two or more MPLS islands belonging to the same MPLS domain through one ASON/GMPLS domain. It is based on the overlay model, where client and server networks do not exchange routing information. The interconnection is firstly done at the control plane level allowing the OSPF-TE flooding mechanism to advertise the existence of a link between two MPLS islands. Then, all MPLS routers in both parts of the MPLS domain know the complete network topology. Moreover, flooding messages advertising topological changes in one MPLS island of the domain are sent to other MPLS islands through these connections. No optical resources are used in the transport plane of the ASON/GMPLS network. New LSPs can be routed end-to-end triggering, if necessary, the establishment of LSPs in the ASON/GMPLS domain.