China Telecom Huawei Technologies Huawei Technologies Enhanced VPNs aim to deliver VPN services with enhanced characteristics, such as guaranteed resources, latency, jitter, etc., so as to support customers requirements for connectivity services with these enhanced characteristics. Enhanced VPN requires integration between the overlay VPN connectivity and the characteristics provided by the underlay network. A Network Resource Partition (NRP) is a subset of the network resources and associated policies on each of a connected set of links in the underlay network. An NRP could be used as the underlay to support one or a group of enhanced VPN services. In some network scenarios, each NRP can be associated with a unique Flexible Algorithm (Flex-Algo), which can provide constraint-path computation based on the customized topological constraints. This document specifies a mechanism to build Segment Routing (SR) based NRPs by combining SR Flex-Algo and IGP L2 bundles with minor extensions.