Nokia Nokia GMPLS-Controlled Optical Networks 4A0-220 Exam Dumps: Updated Questions & Answers (October 2025)

SFD is not a GMPLS protocol, but a term used in optical networks to refer to the Source Frequency Definition, which is a parameter that specifies the frequency of a wavelength channel4. GMPLS protocols are those that enable the control and management of different types of switching technologies, such as packet, wavelength, fiber, and time-slot switching5. Some examples of GMPLS protocols are OSPF-TE, RSVP-TE, and LMP. OSPF-TE is a routing protocol that advertises the topology and the link attributes of the network6. RSVP-TE is a signaling protocol that establishes, modifies, and releases LSPs. LMP is a link management protocol that verifies the connectivity and monitors the status of the links. References:

4: Source Frequency Definition (SFD) - ITU

5: Generalized Multi-Protocol Label Switching - Wikipedia

6: OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS) - RFC 4203

[7]: Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource Reservation Protocol-Traffic Engineering (RSVP-TE) Extensions - RFC 3473

[8]: Link Management Protocol (LMP) - RFC 4204

A distributed control plane for GMPLS means that each router has software to run the GMPLS protocols and can modify the node’s switching fabric. This allows the routers to communicate with each other and establish Label Switched Paths (LSPs) across the network without relying on a centralized controller or network manager. A distributed control plane can improve the scalability, reliability, and efficiency of the network. References : Nokia GMPLS-controlled Optical Networks Course | Nokia, GMPLS - Nokia

Test Mode is a feature of the Link Management Protocol (LMP) that allows testing the connectivity and functionality of a link or a TE-link. Test Mode can be initiated by either end of a link or a TE-link by sending a Test Message with a Test ID and a Test Pattern. The Test Message is sent over the control channel of the link or the TE-link and contains information such as the source and destination IP addresses, the link ID, and the test parameters. The receiving node then verifies the Test Message and sends back a TestStatusAck message with the same Test ID and Test Pattern. The TestStatusAck message indicates whether the test was successful or not, and if not, what was the reason for failure. Test Mode can be used to check if a link or a TE-link is operational, if it has any errors or faults, or if it supports certain features or capabilities. References : Nokia GMPLS-controlled Optical Networks Course | Nokia, RFC 4204 - Link Management Protocol (LMP)

To configure the Trail template in NFM-T for an Uplink board (such as 2UC400) in a network with only LI restoration capability, you need to check the Logical Link box, set the Port Type to Unterminated, uncheck 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 LI restoration. The logical link is not terminated at the Uplink board, but at the OTU board. The ASON Routed option is not needed for LI restoration, as the LSPs are established by NFM-T and not by GMPLS. 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 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 Upstream Label Object in RSVP-TE is an optional object that allows a node to suggest a label to its upstream neighbor for the purpose of provisioning bidirectional LSPs. The upstream label object is carried in the Resv message and contains the label value that the node wants to use for receiving traffic from its upstream neighbor. The upstream neighbor can accept or reject the suggested label based on its local policy and resource availability. The upstream label object simplifies the label allocation process for bidirectional LSPs and avoids the need for additional signaling messages. References : RSVP-TE - Hewlett Packard Enterprise, RSVP - Nokia

Tunnel Property Heritage is a feature of GMRE that allows the propagation of certain properties from higher order (HO) LSPs to lower order (LO) LSPs in a multi-layer network. These properties include cost, SRLG, and color. Cost is a metric that reflects the preference of using a certain link or path for routing. SRLG is a set of links that share a common risk of failure. Color is an attribute that can be used to group or filter LSPs based on service classes or customer profiles. By propagating these properties from HO to LO LSPs, GMRE can ensure that the end-to-end LSPs are consistent and optimal across different layers34. References:

3: Nokia GMPLS-controlled Optical Networks Course | Nokia

4: GMPLS - Nokia

Signaling protocols are protocols that are used by the ingress router to set up a new LSP in an MPLS network. Signaling protocols are responsible for requesting, allocating, and releasing resources along the LSP, as well as establishing and maintaining the label bindings between the nodes. Some examples of signaling protocols are RSVP-TE, LDP, and CR-LDP34. References:

3: Nokia GMPLS-controlled Optical Networks Course | Nokia

4: MPLS Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 7.1.x - Implementing MPLS Label Distribution Protocol [Cisco IOS XR Software (End-of-Sale)] - Cisco

The Feasibility File is a file that contains a set of target values for various optical impairment parameters, such as OSNR, CD, PMD, and PDL, that are used to determine whether a given LSP can be routed through the GMRE network. The Feasibility File is generated by the Network Planning Application (NPA) based on the network design and the service requirements. The Feasibility File is then loaded into the GMRE nodes and used by the GMPLS routing engine to perform feasibility checks for LSP requests. The Feasibility File ensures that the LSPs are routed in accordance with the network plan and the optical performance criteria12. References:

1: Nokia GMPLS-controlled Optical Networks Course | Nokia

2: GMPLS - Nokia