BGP Extensions for Network Resource Partition

Existing approaches bind a Segment Routing (SR) Policy to a Network Resource Partition (NRP) on a one-to-one basis, which lacks flexibility and introduces significant operational overhead as the number of NRPs scales, especially when the NRPs share the same SR Policy path. This document defines BGP extensions to advertise NRP identifier (NRP ID) information between network nodes, which decouples SR Policy from NRP, allowing multiple NRPs to share a common SR Policy path and thus avoiding linear growth of SR Policies. This design reduces operational complexity and is also applicable to SR Best Effort (SR BE) scenario.