http://www.rfc-editor.org/rfc/rfc5441.txt
RFC 5441: A Backward-Recursive PCE-Based Computation (BRPC) Procedure to Compute Shortest Constrained Inter-Domain Traffic Engineering Label Switched Paths, JP. Vasseur, R. Zhang, N. Bitar, JL. Le Roux2009-04-01T23:00:00-00:00The ability to compute shortest constrained Traffic Engineering Label Switched Paths (TE LSPs) in Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) networks across multiple domains has been identified as a key requirement. In this context, a domain is a collection of network elements within a common sphere of address management or path computational responsibility such as an IGP area or an Autonomous Systems. This document specifies a procedure relying on the use of multiple Path Computation Elements (PCEs) to compute such inter-domain shortest constrained paths across a predetermined sequence of domains, using a backward-recursive path computation technique. This technique preserves confidentiality across domains, which is sometimes required when domains are managed by different service providers. [STANDARDS-TRACK]