4A0-220 Nokia GMPLS-Controlled Optical Networks Questions and Answers

To configure the Trail template in NFM-T for an Uplink board (such as 2UC400) in an MRN network with LO and LI restoration capabilities, you need to check the Logical Link box, set the Port Type to Unterminated, check the ASON Routed box, and uncheck the ASON Tunnel box. This configuration allows you to create a logical link between two Uplink boards that can be used for LO or LI restoration. The logical link is not terminated at the Uplink board, but at the OTU board. The ASON Routed option enables the GMPLS control plane for the logical link, while the ASON Tunnel option is not applicable for Uplink boards.  References  :  Nokia Advanced Optical Network Management with NFM-T Course | Nokia ,  Nokia 1830 PSS-4, PSS-8, PSS-16 and PSS-32 Platforms - NATO

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 quality 1 2 .  References :

1 : Nokia GMPLS-controlled Optical Networks Course | Nokia

2 : Nokia Network Functions Manager for Transport User Guide | Nokia

In a 1830PSS MRN network, groups of links can be combined (bundled) together in a single TE-Link both within layer 0 and 1 networks. A TE-Link is a logical representation of one or more physical links that share the same attributes and can be used to establish Label Switched Paths (LSPs). A TE-Link can be either single-layer or multi-layer, depending on the switching capabilities of the links. In a single-layer TE-Link, all the links belong to the same layer, either layer 0 (optical) or layer 1 (OTN). In a multi-layer TE-Link, the links belong to different layers, such as layer 0 and layer 1. A TE-Link can be either bundled or unbundled, depending on the number of links it contains. A bundled TE-Link contains more than one link, while an unbundled TE-Link contains only one link. A bundled TE-Link can provide more bandwidth and flexibility than an unbundled TE-Link.  References  :  Nokia GMPLS-controlled Optical Networks Course | Nokia ,  3. GMPLS - Nokia

The SNC Nominal Route is the default or preferred route that is assigned to an LSP when it is created. The SNC Nominal Route is determined by the constraints that are specified by the user during the LSP creation process, such as cost, SRLG, color, bandwidth, protection, and regeneration. The user can modify the SNC Nominal Route in NFM-T by using the Constraint Wizard, which is a tool that allows the user to change the constraints for an existing LSP.  The Constraint Wizard will then compute a new SNC Nominal Route based on the modified constraints and update the LSP accordingly 3 4 .  References :

3 : Nokia GMPLS-controlled Optical Networks Course | Nokia

4 : Nokia Network Functions Manager for Transport User Guide | Nokia

GMPLS-enabled nodes use routing protocols, such as OSPF-TE or ISIS-TE, to exchange information about the topology and the state of the links in the network 1 2 .  This information includes the link attributes, such as bandwidth, wavelength, protection, and shared risk link groups (SRLGs) 3 . The state of each link indicates whether it is up or down, available or reserved, and so on. This information is used by GMPLS-enabled nodes to compute feasible paths for LSPs and to avoid routing loops or conflicts. The bandwidth and the frequency of each client path are not present in every GMPLS-enabled node, but only in the ingress and egress nodes that initiate and terminate the LSPs. The list of LSPs created in the entire network is also not present in every GMPLS-enabled node, but only in the nodes that are involved in the LSPs or that maintain a global view of the network.  References :

1 : GMPLS - Nokia

2 : Generalized Multi-Protocol Label Switching - Wikipedia

3 : Nokia GMPLS-controlled Optical Networks Course | Nokia

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 GMRE node address is the IP address for communication between network elements (NEs) in a GMPLS-controlled optical network. The GMRE node address is also known as the GMRE loopback address or the GMPLS node IP. It is used by GMPLS protocols such as LMP and RSVP to identify and communicate with other GMRE nodes. The GMRE node address is configured on each NE and is advertised by OSPF-TE to other nodes in the same area.  References  :  Nokia 1830 PSS-4, PSS-8, PSS-16 and PSS-32 Platforms - NATO ,  1830 PSS Identifiers

The GMPLS technology includes three categories of protocols: routing, signaling, and link management. Routing protocols are used to exchange information about the network topology, resources, and constraints among the nodes. Signaling protocols are used to establish, modify, and release Label Switched Paths (LSPs) across the network. Link management protocols are used to verify the connectivity and status of the links between adjacent nodes.  References  :  Nokia GMPLS-controlled Optical Networks Course | Nokia ,  3. GMPLS - Nokia

The Shutting Down state is a transient state that occurs when a TE-link is set to maintenance mode in the NFM-T. In this state, the TE-link is not available for routing new LSPs, but the existing LSPs (SNCs) that use the TE-link are not immediately terminated. Instead, they are soft-rerouted, which means that they are gracefully switched to alternative paths without disrupting the traffic. The Shutting Down state lasts until all the SNCs on the TE-link are successfully soft-rerouted or forcefully terminated.  After that, the TE-link transitions to the Administrative Maintenance state, where no traffic can be routed over the TE-link 1 2 .  References :

1 : Nokia GMPLS-controlled Optical Networks Course | Nokia

2 : Nokia Network Functions Manager for Transport User Guide | Nokia