Extending OSPF routing protocol for shared mesh restoration

Efficient methods are needed to aggregate and disseminate the routing information, including the optical link resource availability and sharing, so that the amount advertised by the routing protocol is minimized and the information necessary for path computation is not lost. In this paper, the author proposed to extend the generalized multi-protocol label switching (GMPLS) OSPF-TE routing protocol to carry the necessary sharing information of the reserved resource on a TE link in support of computing the shared mesh restored paths. It is based on the OSPF routing extensions required to support traffic engineering (TE) and GMPLS. New optional sub-TLVs (type/length/value) are added to the link TLV of the TE link state advertisements (LSA) so that the sharing information of the restoration resource is disseminated.