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

The Soft Shutting Down state in the NFM-T is an administrative maintenance state where services stay up but no new traffic can be routed over the TE-link. This state is used to prepare a TE-link for maintenance or decommissioning without affecting the existing services. The NFM-T sets the TE-link to Soft Shutting Down state by sending a Notify message with the Administrative State Change flag to the head-end node of the TE-link. The head-end node then stops accepting new LSP requests over the TE-link and sends a PathErr message with the Administrative State Change flag to all the tail-end nodes of the LSPs in the TE-link. The tail-end nodes then stop sending new traffic over the LSPs and send a ResvErr message with the Administrative State Change flag to all the intermediate nodes of the LSPs. The intermediate nodes then update their routing tables and stop forwarding new traffic over the LSPs. The existing traffic, however, continues to flow over the LSPs until they are manually deleted or rerouted by the NFM-T. References : Nokia GMPLS-controlled Optical Networks Course | Nokia, Nokia Advanced Optical Network Management with NFM-T Course | Nokia

The Link Maintenance window is a feature of NFM-T that allows the user to perform maintenance tasks on links and nodes in a GMPLS network. The Link Maintenance window is a wizard that provides commands to set links and nodes to maintenance mode, which prevents them from being used for routing new LSPs or carrying traffic. The user can also use the Link Maintenance window to reroute existing LSPs away from the links and nodes that are in maintenance mode, either manually or automatically. The Link Maintenance window helps the user to perform network maintenance operations without disrupting the service availability or quality12. References:

• 1: Nokia GMPLS-controlled Optical Networks Course | Nokia
• 2: Nokia Network Functions Manager for Transport User Guide | Nokia

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

Quality of Service (QoS) in GMPLS is the ability to set constraints such as latency and priority for different kinds of services. This means that GMPLS can allocate network resources according to the specific requirements of each service, such as voice, video, or data. For example, a voice service may need low latency and high priority, while a data service may need high bandwidth and low priority. GMPLS can use Traffic Engineering (TE) extensions to OSPF and RSVP protocols to advertise and reserve network resources based on QoS parameters. References : [Nokia GMPLS-controlled Optical Networks Course | Nokia], [Quality of Service - Nokia]

The SNC state with an uppercase “N” means that the resource is currently using the nominal resource assigned to it. As explained in the previous question, a nominal resource is the default or preferred resource that is assigned to an LSP when it is created. If an LSP is using the nominal resource on a TE-link, it means that the LSP has not been rerouted or switched due to any failure or constraint violation. In this case, the SNC state of the resource will be “N”, indicating that it is in use by an LSP12. References:

• 1: Nokia GMPLS-controlled Optical Networks Course | Nokia
• 2: Nokia Network Functions Manager for Transport User Guide | Nokia