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

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

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

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