China Telecom 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 on 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 logical network topology. This document describes a mechanism to build the SR based NRPs using IS-IS Multi-Topology together with other well-defined IS-IS extensions.