Re: [Lsr] I-D Action: draft-ietf-ospf-mpls-elc-15.txt

[wangyali <[e-mail]>]

Hi authors,

After reading this draft, I am not clear with following points.

First,  as said " Even though ELC is a property of the node, in some cases it is advantageous to associate and advertise the ELC with a prefix.", what are "some cases" in which it is advantageous to associate and advertise the ELC with a prefix? And ELC is a property of the node, why don't extend the OSPF RI Opaque LSA to carry ELC?

Second, as said " If a router has multiple interfaces, the router MUST NOT announce ELC unless all of its interfaces are capable of processing ELs. ", why do not consider ELC advertisement in link granularity? 

Third, as said " If the router supports ELs on all of its interfaces, it SHOULD advertise the ELC with every local host prefix it advertises in OSPF.", what is the "every local host prefix"?

Last one, as defined that ERLD is advertised in a Node MSD TLV, why the ERLD-MSD type can be received in the OSPFv2 or OSPFv3 Link MSD sub-TLV? " When the ERLD-MSD type is received in the OSPFv2 or OSPFv3 Link MSD Sub-TLV [RFC8476], it MUST be ignored."

Best regards,
Yali

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Subject: [Lsr] I-D Action: draft-ietf-ospf-mpls-elc-15.txt


A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Link State Routing WG of the IETF.

        Title           : Signaling Entropy Label Capability and Entropy Readable Label Depth Using OSPF
        Authors         : Xiaohu Xu
                          Sriganesh Kini
                          Peter Psenak
                          Clarence Filsfils
                          Stephane Litkowski
                          Matthew Bocci
	Filename        : draft-ietf-ospf-mpls-elc-15.txt
	Pages           : 9
	Date            : 2020-06-01

Abstract:
   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 Label Switched Path (LSP) unless an egress LSR has indicated
   via signaling that it has the capability to process ELs, referred to
   as the Entropy Label Capability (ELC), on that LSP.  In addition, it
   would be useful for ingress LSRs to know each LSR's capability for
   reading the maximum label stack depth and performing EL-based load-
   balancing, referred to as Entropy Readable Label Depth (ERLD).  This
   document defines a mechanism to signal these two capabilities using
   OSPFv2 and OSPFv3 and BGP-LS.


The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-ietf-ospf-mpls-elc/

There are also htmlized versions available at:
https://tools.ietf.org/html/draft-ietf-ospf-mpls-elc-15
https://datatracker.ietf.org/doc/html/draft-ietf-ospf-mpls-elc-15

A diff from the previous version is available at:
https://www.ietf.org/rfcdiff?url2=draft-ietf-ospf-mpls-elc-15


Please note that it may take a couple of minutes from the time of submission until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:
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