The framework for MPLS in transport networks (RFC 5921) provides
reference models for the MPLS Transport Profile (MPLS-TP) Transport
Service Interfaces, which are a User-to-Network Interface (UNI), and
a Network-to-Network Interface (NNI). This document updates those
reference models to show detailed reference points for these
interfaces, along with further clarification of the functional
architecture of MPLS-TP at a UNI and NNI.
This document is a product of a joint Internet Engineering Task Force
(IETF) / International Telecommunication Union Telecommunication
Standardization Sector (ITU-T) effort to include an MPLS Transport
Profile within the IETF MPLS and Pseudowire Emulation Edge-to-Edge
(PWE3) architectures to support the capabilities and functionalities
of a packet transport network as defined by the ITU-T. This document
is not an Internet Standards Track specification; it is published for
informational purposes.