4A0-220 Exam Dumps : Nokia GMPLS-Controlled Optical Networks

The GMRE notify address is an IP address used to signal failures on downstream nodes upstream to the head node. The GMRE notify address is configured on each GMRE node and is used to send a Notify message to the head node when a failure occurs on a link or node alongthe LSP. The Notify message contains the failure information and the LSP ID. The head node can then initiate a restoration process based on the Notify message. References : Nokia GMPLS-controlled Optical Networks Course | Nokia, GMPLS - Nokia

A network with ROADM GMPLS nodes and optical transponder connections could have both L0 and L1 restoration capabilities. L0 restoration refers to the ability of the network to recover from failures at the optical layer, such as fiber cuts or node failures, by rerouting the affected LSPs to alternative paths at the same layer. L0 restoration can be achieved by using GMPLS signaling protocols, such as RSVP-TE or CR-LDP, to establish backup LSPs in advance or on demand. L0 restoration can provide fast recovery times and high availability for optical services34. L1 restoration refers to the ability of the network to recover from failures at the sub-wavelength layer, such as transponder failures or wavelength unavailability, by rerouting the affected LSPs to alternative paths at a higher layer. L1 restoration can be achieved by using GMPLS routing protocols, such as OSPF-TE or ISIS-TE, to advertise the sub-wavelength information and availability to other nodes in the network. L1 restoration can provide more flexibility and efficiency for sub-wavelength services56. References:

• 3: GMPLS - Nokia
• 4: Generalized Multi-Protocol Label Switching - Wikipedia
• 5: Sub-Wavelength Switching - Nokia
• 6: Sub-Wavelength Switching in Optical Networks - IEEE Xplore

GMPLS stands for Generalized Multi-Protocol Label Switching, which is a protocol suite that extends MPLS to control different types of switching technologies, such as optical, TDM, and packet switching1. The meaning of Generalized in GMPLS is that it can be used for traffic types other than data packets, such as wavelengths, time slots, or fibers2. GMPLS can also use implicit labels that are derived from the physical properties of the data stream, such as wavelength or timeslot, instead of explicit labels that are carried in the packet header3. This allows GMPLS to support various transport networks and applications, such as optical transport networks (OTN), wavelength switched optical networks (WSON), and automatic switched optical networks (ASON)4. References:

• 1: Nokia GMPLS-controlled Optical Networks Course | Nokia
• 2: What is MPLS and GMPLS? - Metaswitch
• 3: Generalized Multi-Protocol Label Switching - Wikipedia
• 4: GMPLS - Nokia