When nodes that support generalized multi-protocol label switching (GMPLS) are introduced into existing networks, the GMPLS nodes co-exist with conventional Internet protocol (IP) and multi-protocol label switching (MPLS) (IP+MPLS) nodes that do not support GMPLS. In this case, the GMPLS nodes must Interwork with IP+MPLS nodes. This paper proposes an architecture for GMPLS and IP+MPLS inter-working based on extended routing and signaling. In the extended routing, information about some nodes and links in a GMPLS network emulates information that can be understood by IP+MPLS nodes. The emulated information is advertised to the IP+MPLS network. In the extended signaling, MPLS signaling packets are forwarded to the GMPLS data plane. An MPLS label switched path (LSP) is established through a GMPLS LSP tunnel. As a result, the IP+MPLS network can interwork with the GMPLS network without upgrading the IP+MPLS nodes. We developed GMPLS prototype nodes that support this interworking architecture and show interworking experimental results.