This document specifies the Generalized Multi-Protocol Label Switching (GMPLS) architecture, which extends the Multi-Protocol Label Switching (MPLS) architecture to support a broader range of switching and forwarding hierarchies. GMPLS allows for the dynamic provisioning of resources and network survivability using protection and restoration techniques. The architecture is designed to handle time-division, wavelength, and spatial switching, and focuses on the control plane, which includes signaling and routing protocols. Key extensions to MPLS-TE are highlighted, such as the ability to support non-packet-based forwarding planes and the extension of signaling and routing protocols to accommodate these new types of links. The document also discusses the use of unnumbered links and link bundling to improve scalability, and the relationship between GMPLS and the User to Network Interface (UNI). Additionally, it covers link management procedures, including control channel management, link connectivity verification, and fault management, using the Link Management Protocol (LMP).This document specifies the Generalized Multi-Protocol Label Switching (GMPLS) architecture, which extends the Multi-Protocol Label Switching (MPLS) architecture to support a broader range of switching and forwarding hierarchies. GMPLS allows for the dynamic provisioning of resources and network survivability using protection and restoration techniques. The architecture is designed to handle time-division, wavelength, and spatial switching, and focuses on the control plane, which includes signaling and routing protocols. Key extensions to MPLS-TE are highlighted, such as the ability to support non-packet-based forwarding planes and the extension of signaling and routing protocols to accommodate these new types of links. The document also discusses the use of unnumbered links and link bundling to improve scalability, and the relationship between GMPLS and the User to Network Interface (UNI). Additionally, it covers link management procedures, including control channel management, link connectivity verification, and fault management, using the Link Management Protocol (LMP).