Re: [lisp] Mirja Kühlewind's Discuss on draft-ietf-lisp-rfc6830bis-16: (with DISCUSS and COMMENT)

[Dino Farinacci <[e-mail]>]

> PROPOSED
> "The 'Explicit Congestion Notification' (ECN) field (bits 6 and 7
>      of the IPv6 'Traffic Class' field) [RFC3168] requires special treatment in
>      order to preserve the use of ECN on the path.
>      ITR encapsulation MUST copy the 2-bit 'ECN' field from the inner
>      header to the outer header, inline with the ’Normal Mode’ in section 4.1 
>      of [RFC6040].  Re-encapsulation SHOULD follow the decapsulation as described 
>      below and then 2-bit 'ECN' field from the stripped inner header to the 
>      new outer header.“

I did not include this text because the last sentence is not formed well. Please restate. A verb is missing.

> "The 'Explicit Congestion Notification' (ECN) field (bits 6 and 7
>      of the IPv6 'Traffic Class' field) requires special treatment on 
>      decapsulation in
>      order to avoid discarding indications of congestion, 
>      inline with section 4.2 of [RFC6040]. If
>      the 'ECN‘ field of the outer header contains a congestion indication 	
>      codepoint (the
>      value is '11', the Congestion Experienced (CE) codepoint) and the inner 
>      header indicates ECN support (either ECT(0) or ECT(1) codepoint is set), 
>      then ETR decapsulation MUST also set CE field in the inner header that is 
>      used
>      to forward the packet beyond the ETR. If the inner packet is marked as non-
>      ECT but the outer header has the CE mark set, the packet MUST be dropped 
>      instead. Any discrepancy between the inner and outer header for non-ECT, 
>      ECT(0) and ECT(1) MUST NOT be copied from the outer header. These 
>      requirements preserve
>      CE indications when a packet that is ECN-capable traverses a LISP tunnel
>      and becomes marked with a CE indication due to congestion between
>      the tunnel endpoints or transforms an CE into loss if that packet is not 
>      ECN-capable conserving the congestion indication towards a non-ECN enables 
>      endpoint.”

I didn’t include this text because (1) it under states what to do with IPv4, (2) it has too much detail that is already in RFC6040, and (3) it undoes text that other reviewers have offered.


> Please also remove the duplicated text after these bullet lists in the draft!

You have to tell me what text. I am too confused at this point on what you want.

> Further I believe my discuss points 2) and 4) are not fully resolved yet. Also I would like to at least see more explanation about the approach for extensibility that was taken in this doc (point 6).

You are going to have to repeat what they are because too many emails have flown by since your initial post. And for extensibility, we discuss it in RFC8060 and don’t think anything more should be said here otherwise, we will duplicate unnecessary text.

Another new diff file enclosed.

Dino