MPLS-TP Technology: Characteristics and Benefits

MPLS-TP Technology


Which two characteristics of the MPLS-TP technology are true? (Choose two.)



Click on the arrows to vote for the correct answer

A. B. C. D. E.


MPLS-TP (Multiprotocol Label Switching - Transport Profile) is a network protocol that combines the benefits of MPLS and traditional transport technologies to provide efficient, scalable, and reliable packet transport services in core and transport networks. Here are the explanations of the two characteristics of MPLS-TP that are true:

A. Dynamic control plane: MPLS-TP employs a dynamic control plane that enables the automatic discovery, setup, and management of Label Switched Paths (LSPs) between network nodes. The control plane is responsible for signaling and routing LSPs, distributing labels, and managing network resources. MPLS-TP uses a distributed control plane based on the Resource Reservation Protocol - Traffic Engineering (RSVP-TE) and the Intermediate System to Intermediate System (IS-IS) routing protocol. The dynamic control plane in MPLS-TP simplifies network operations, enhances scalability, and enables fast service provisioning and restoration.

C. Out-of-band OAM: MPLS-TP provides out-of-band Operations, Administration, and Maintenance (OAM) mechanisms that enable network operators to monitor, diagnose, and troubleshoot network performance and faults. The out-of-band OAM allows operators to send and receive OAM packets that are separated from user traffic, ensuring that OAM functions do not affect the user traffic. MPLS-TP supports various OAM functions, including continuity check, connectivity verification, fault management, performance monitoring, and protection switching. The out-of-band OAM in MPLS-TP enhances network availability, reliability, and manageability.

Therefore, the correct answers are A and C.

Here are the explanations for the incorrect answers:

B. Connectionless packet switching model: MPLS-TP uses a connection-oriented packet switching model, where data packets are encapsulated with labels that identify the LSPs between network nodes. The connection-oriented model enables traffic engineering, quality of service, and path protection in the network.

D. Point-to-multipoint unidirectional LSP: MPLS-TP supports various types of LSPs, including point-to-point, point-to-multipoint, and multipoint-to-multipoint, but all LSPs are bidirectional. The point-to-multipoint LSP is a unidirectional LSP that originates from one node and terminates at multiple nodes, but it requires a separate reverse LSP for the return traffic.

E. 1:1, 1+1, and 1:N protection options: MPLS-TP supports various protection mechanisms, including 1:1, 1+1, and 1:N, which are used to protect against link, node, or LSP failures. The protection mechanisms use backup LSPs to switch the traffic in case of failures, ensuring service continuity. However, the protection options are not a characteristic of MPLS-TP itself but rather a feature that is enabled by the MPLS-TP implementation.