GMPLS: Generalized Multiprotocol Label Switching

GMPLS: Generalized Multiprotocol Label Switching
Generalized Multiprotocol Label Switching (GMPLS) enhances MPLS architecture by the complete separation of the control and data planes of various networking layers. GMPLS enables a seamless interconnection and convergence of new and legacy networks by allowing end-to-end provisioning, control and traffic engineering even when the start and the end nodes belong to heterogeneous networks.  

GMPLS is based on the IP routing and addressing models. This assumes that IPv4 and/or IPv6 addresses are used to identify interfaces but also that traditional (distributed) IP routing protocols are reused. The common control plane promises to simplify network operation and management by automating end-to-end provisioning of connections, managing network resources, and providing the level of QoS that is expected in the new applications.  
While the technology used by the GMPLS control plane remains IP-based, the data plane (traffic plane) can now diversify to include more varieties of traffic (TDM, Lambda, packet, and fiber, etc). Generalized MPLS (GMPLS) supports multiple types of switching, i.e., the addition of support for TDM, lambda, and fiber (port) switching. In summary, GMPLS extends MPLS functionality by establishing and provisioning paths for:  
  • TDM paths, where time slots are the labels (SONET).
  •  FDM paths, where electromagnetic frequency is the label (light waves).
  •  Space division multiplexed paths, where the label indicates the physical position of data (Photonic Cross-connect).
GMPLS is based on the Traffic Engineering (TE) extensions to  MPLS(MPLS-TE). The biggest addition in the GMPLS protocol suite is a new signaling protocol, Link Management Protocol (LMP), to establish, release and manage connections between two adjacent GMPLS-capable nodes. Other protocols RSVP-TE, OSPF-TE, CR-LDP and IS-IS-TE, where OSPF-TE and IS-IS-TE are extended from the original protocols for GMPLS, are used in the GMPLS architecture.
Protocol Structure - Generalized Multiprotocol Label Switching (MPLS)
GMPLS Protocol Suite Overview

Routing protocols for the auto-discovery of network topology, advertise resource availability.
Signaling protocols for the establishment of traffic-engineered LSPs.
Link Management
  • Control-Channel Management
  • Link-Connectivity Verification
  • Link-Property Correlation
  • Fault Isolation
GMPLS architecture arc is defined by IETF ( ) RFC 3945.
Reference : Multiprotocol Label Switching Architecture Generalized Multi-Protocol Label Switching (GMPLS) Architecture