Segment Routing is one of the new kids on the block in the routing area, and perfectly fits both the paradigm of autonomous networking, and the SDN approach with centralized and application-driven path control. In this document, I would like to share an introduction to Segment Routing, its roots, and its applications.
Segment Routing heavily reuses concepts from another two major technologies – Multi Protocol Label Switching (MPLS), and Source Routing. It is therefore advantageous to revisit their most important properties.
MPLS – A Quick Review
This article assumes basic understanding of MPLS inner mechanisms and forwarding process. For an introduction into MPLS in a manageable and not-burdensome way, I invite you to read a blog written earlier: MPLS History and building blocks
https://learningnetwork.cisco.com/s/blogs/a0D3i0000002SKP6EA0/introduction-to-segment-routing