2. Segment Routing MPLS (SR-MPLS)

2.1 Overview

Segment Routing MPLS (SR-MPLS) is an evolution of MPLS :

• SR-MPLS does not change the MPLS architecture [ RFC 3031 ] ;

• SR-MPLS does not change the MPLS switching plan and therefore does not require any hardware changes;

• SR-MPLS requires an upgrade of the MPLS control plane, and therefore a software upgrade of the routers.

SR-MPLS is based on two principles:

1) MPLS labels are no longer advertised in an MPLS-specific signalling protocol but are advertised in the internal link-state routing protocol, such as IS-IS [