Re: [OSPF] Signaling Entropy Label Capability Using OSPF - draft-ietf-ospf-mpls-elc-00

Xuxiaohu <> Wed, 13 April 2016 07:42 UTC

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From: Xuxiaohu <>
To: "Acee Lindem (acee)" <>, "" <>
Thread-Topic: Signaling Entropy Label Capability Using OSPF - draft-ietf-ospf-mpls-elc-00
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Date: Wed, 13 Apr 2016 07:41:36 +0000
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Subject: Re: [OSPF] Signaling Entropy Label Capability Using OSPF - draft-ietf-ospf-mpls-elc-00
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Hi Acee,

Thanks for your comments. Please see my response in line.

> -----Original Message-----
> From: Acee Lindem (acee) []
> Sent: Tuesday, April 12, 2016 1:39 AM
> To:
> Cc: OSPF WG List
> Subject: Signaling Entropy Label Capability Using OSPF -
> draft-ietf-ospf-mpls-elc-00
> Authors,
> We will soon be progressing the OSPFv2 SR draft. What is your intent for this
> draft? It is missing:
>     1. A figure with the RI encoding like other OSPF documents

Will add two figures for ELC TLV and RLSDC TLV respectively.

>     2. Discussion as to precisely how the capability would be used by a router in
> an OSPF routing domain. For example, must a router remove the EL if the
> next-hop doesn’t support it?

This document only describes how the ELC and RLSDC are advertised via OSPF. As for how these capabilities would be used are actually described in By the way, a router doesn't need to remove the EL if the next-hop doesn't support it. The only requirement on using EL is: An ingress LSR cannot insert ELs for packets going into a given tunnel unless an egress LSR has indicated via signaling that it can process ELs on that tunnel.

>     3. A discussion of backward compatibility for the new Router-Information
> LSA capability.

Is it enough to add the following text:

"To be compatible with RFC7770, ELC and RLSDC TLVs SHOULD continue to be advertised in the first instance, i.e., 0, of the Router Information LSA."

Best regards,

> Thanks,
> Acee