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

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

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]

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