The Nokia GMPLS-Controlled Optical Networks (4A0-220)

The provisioning steps that are common in both CP to plain MP networks are node creation, CPB provisioning process, node synchronization, and CPB power balance. These steps are required to create and commission the nodes, provision the cross-connect boards (CPBs), associate the links between the nodes, synchronize the network elements (NEs) with the NFM-T, and balance the power levels of the CPBs.  References  :  Nokia GMPLS-controlled Optical Networks Course | Nokia ,  Nokia Advanced Optical Network Management with NFM-T Course | Nokia

Preemption is a mechanism that allows a higher priority LSP to tear down an existing lower priority LSP in order to obtain the required resources for its establishment. Preemption can occur when there is not enough bandwidth or other resources available on a link or node to accommodate a new LSP request. In this case, the node can select one or more lower priority LSPs that are using the resources and send them a PathErr message with a Preempt error code. This causes the lower priority LSPs to be terminated and release their resources.  The node can then allocate the resources to the higher priority LSP and send a Resv message to confirm its reservation 3 4 .  References :

3 : RFC 4829: Label Switched Path (LSP) Preemption Policies for MPLS Traffic Engineering 4

4 : MPLS Applications User Guide | Juniper Networks 5

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

A Nominal Route in a GMPLS network is the optimal path that meets the Traffic Engineering (TE) constraints for a given LSP request. A Nominal Route is calculated by the NFM-T using the Constrained Shortest Path First (CSPF) algorithm, which takes into account parameters such as bandwidth, latency, priority, protection type, and other QoS attributes. A Nominal Route is stored in the NFM-T database and can be used to provision LSPs over the network. A Nominal Route can differ from the Current Route, which is the actual path that the LSP is taking at a given time, due to network changes or failures.  References  :  Nokia GMPLS-controlled Optical Networks Course | Nokia ,  Nokia Advanced Optical Network Management with NFM-T Course | Nokia

The equipment vendor is not a parameter that is considered when restoring an LSP. Restoration is the process of re-establishing an LSP after a failure by using an alternative path that meets the same constraints as the original LSP. The parameters that are considered when restoring an LSP include coloring, reservation priority, maximum latency, bandwidth, protection type, and other QoS attributes. The equipment vendor does not affect the restoration process as long as the nodes support GMPLS protocols and interoperate with each other.  References  :  RFC 4427 - Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS) , [Nokia GMPLS-controlled Optical Networks Course | 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 layers 3 4 .  References :

3 : Nokia GMPLS-controlled Optical Networks Course | Nokia

4 : GMPLS - 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 channel 4 .  GMPLS protocols are those that enable the control and management of different types of switching technologies, such as packet, wavelength, fiber, and time-slot switching 5 . 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 network 6 . 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 Label Switched Path (LSP) is the path created by MPLS nodes that use labels to forward packets across the network. A label is a short identifier that is attached to each packet and indicates the next hop or destination of the packet. The nodes use a label forwarding table to switch packets based on their labels, without inspecting the packet headers. This can improve the performance, security, and quality of service of the network. An LSP can be established by using GMPLS protocols such as OSPF-TE and RSVP-TE, which exchange information about the network topology, resources, and constraints.  References  :  Nokia GMPLS-controlled Optical Networks Course | Nokia ,  GMPLS - Nokia

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