Question

A service provider runs IS-IS with Segment Routing on an IOS XR backbone. The network team wants latency-sensitive voice traffic to follow paths computed using a delay metric, while all other traffic continues to use the standard IGP metric — without deploying a separate PCE or explicit SR-TE policies with per-hop segment lists. Which Segment Routing mechanism satisfies this requirement?

Accepted Answer

Flexible Algorithm (Flex-Algo) with a Prefix-SID allocated per algorithm using the min-unidirectional-link-delay metric

Answer

A single global Anycast-SID advertised by all core routers to steer voice traffic

Answer

Topology-Independent Loop-Free Alternate (TI-LFA) configured on all core interfaces

Answer

An adjacency-SID stack manually pushed at the ingress PE for every voice flow