GMPLSGeneralized MPLS differs from traditional MPLS<ref>RFC 3945 "1.2. Multiple Types of Switching and Forwarding Hierarchies"</ref> in asthat it supports multiple types of switching., In particulari.e., GMPLS offers the additionaladdition of support for [[TDM]], wavelengthlambda, and fiber (port) switching''<ref>L. Berger,The "Generalizedsupport Multi-Protocolfor Labelthe Switchingadditional types of switching has driven (GMPLS)Signalingto Functionalextend Description",certain RFCbase 3471functions of traditional MPLS and, Jan.in 2003some cases, IETFto add functionality.</ref>
These changes and additions impact basic LSP properties: how labels are requested and communicated, the unidirectional nature of LSPs, how errors are propagated, and information provided for synchronizing the ingress and egress LSRs.
GMPLS architecture clearly separates the control plane and the forwarding plane. In addition, it also clearly separates the control plane in two parts, the signaling plane containing the signaling protocols and the routing plane containing the routing protocols. <ref>RFC 3945</ref>
