Path Segment in MPLS Based Segment Routing Network

Document Type Replaced Internet-Draft (spring WG)
Authors Weiqiang Cheng  , Lei Wang  , Han Li  , Mach Chen  , Rakesh Gandhi  , Royi Zigler  , Shuangping Zhan 
Last updated 2019-03-07 (latest revision 2018-10-18)
Replaced by draft-ietf-spring-mpls-path-segment
Stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Expired & archived
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Stream WG state Adopted by a WG
Document shepherd No shepherd assigned
IESG IESG state Replaced by draft-ietf-spring-mpls-path-segment
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


A Segment Routing (SR) path is identified by an SR segment list, one or partial segments of the list cannot uniquely identify the SR path. Path identification is a pre-requisite for various use-cases such as performance measurement (PM) of an SR path. This document defines a new type of segment that is referred to as Path Segment, which is used to identify an SR path. When used, it is inserted at the ingress node of the SR path and immediately follows the last segment of the SR path. The Path Segment will not be popped off until it reaches the egress node of the SR path. Path Segment can be used by the egress node to implement path identification hence to support various use-cases including SR path PM, end-to-end 1+1 SR path protection and bidirectional SR paths correlation.


Weiqiang Cheng (
Lei Wang (
Han Li (
Mach Chen (
Rakesh Gandhi (
Royi Zigler (
Shuangping Zhan (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)