Signaling Entropy Label Capability and Entropy Readable Label-stack Depth Using OSPF

Document Type Expired Internet-Draft (lsr WG)
Last updated 2019-03-28 (latest revision 2018-09-24)
Stream IETF
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Expired & archived
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Stream WG state WG Document (wg milestone: Jun 2016 - Standardize OSPF Ent... )
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IESG IESG state Expired
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Multiprotocol Label Switching (MPLS) has defined a mechanism to load balance traffic flows using Entropy Labels (EL). An ingress Label Switching Router (LSR) cannot insert ELs for packets going into a given tunnel unless an egress LSR has indicated via signaling that it has the capability of processing ELs, referred to as Entropy Label Capability (ELC), on that tunnel. In addition, it would be useful for ingress LSRs to know each LSR's capability of reading the maximum label stack depth and performing EL-based load-balancing, referred to as Entropy Readable Label Depth (ERLD), in the cases where stacked LSPs are used for whatever reasons. This document defines mechanisms to signal these two capabilities using OSPF. These mechanisms are useful when the label advertisement is also done via OSPF. In addition, this document introduces the Non-IGP Functional Capabilities TLV for advertising OSPF router's actual non-IGP functional capabilities. ELC is one of such non-IGP functional capabilities.


Xiaohu Xu (
Sriganesh Kini (
Siva Sivabalan (
Clarence Filsfils (
Stephane Litkowski (

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