Flex-Algo LSPs are a type of LSP that allows for greater flexibility in configuring traffic engineering constraints. This is because flex-algo LSPs can be configured with a unique set of traffic engineering constraints for each LSP, whereas SR-TE LSPs use a predefined set of traffic engineering constraints that applies to all LSPs.

Label stack size of the encapsulated data packets, List of traffic-engineering constraint types available to choose from, and Ability to associate one primary and up to two secondary paths to the same LSP are not the advantages of flex-algo LSPs over SR-TE LSPs.

Shared-Risk-Link Groups(SRLG) is taken into account when calculating both primary and secondary path to avoid routing over the same physical link.

PCE does not have the capability to reserve bandwidth, This is a function of a Resource Reservation Protocol (RSVP) or a Label Distribution Protocol (LDP) and is done locally on the PE.

PCE can have advantages such as:

The ability to create cross-area TE-constrained LSP paths

The ability to create LSPs with primary and secondary paths

The ability to ensure that some LSP paths are disjoint

it can be used to optimize the path computation by centralizing the path calculation and by taking into account a global view of the network.

The data is transparently carried from end to end: This statement is not true, MPLS does not provide data transparency, which means that the data is not carried unmodified from end to end. MPLS uses labels to forward data, so the original IP packets are encapsulated in new MPLS packets, and the original IP headers are not visible at the egress LSR.

In SR-TE, routers need to advertise certain attributes of their links to other routers in the network in order to calculate traffic-engineered paths. These attributes include:

Administrative groups that each link belongs to: This information is used to restrict the use of certain links to specific traffic types or groups.

TE metric of links: This information is used to calculate the cost of using a particular link for a traffic-engineered path.

Bandwidth availability of each link: This information is used to control the amount of traffic that can be sent over a particular link.

SRLG that each link belongs to: This information is used to avoid routing over the same physical link. Link status up/down is not needed to be advertised as it is part of the IGP protocol and is used to check the reachability of a link.

Seamless-BFD is a mechanism that allows the detection of faults in MPLS LSPs more quickly by using BFD (Bidirectional Forwarding Detection) protocol. Seamless-BFD responses are sent back using the MPLS data-plane, not the LSP label stack.

An Adjacency-SID does not have to be configured: this statement is not true, An Adjacency-SID is associated with a neighbor router, it is used to identify an adjacency between two routers. An Adjacency-SID must be configured to identify the adjacency.

On a Nokia 7750 SR, R-LFA and TI-LFA cannot be enabled independently; they must be enabled together. The parameter "max-sr-frr-labels" limits the number of labels that R-LFA can add to the data packet encapsulation.

Enable interfaces used for Segment Routing under: This step is not required, enabling interfaces used for Segment Routing is not necessary as the IS-IS protocol already takes care of the flooding of the routing information.