rfc-6882
Support for Resource Reservation Protocol Traffic Engineering (RSVP-TE) in Layer 3 Virtual Private Networks (L3VPNs)
IP Virtual Private Networks (VPNs) provide connectivity between sites across an IP/MPLS backbone. These VPNs can be operated using BGP/MPLS, and a single Provider Edge (PE) node may provide access to multiple customer sites belonging to different VPNs.
The VPNs may support a number of customer services, including RSVP and Resource Reservation Protocol Traffic Engineering (RSVP-TE) traffic. This document describes how to support RSVP-TE between customer sites when a single PE supports multiple VPNs and labels are not used to identify VPNs between PEs.