Re: [lisp] [RTG-DIR} RtgDir last call review: draft-ietf-lisp-signal-free-multicast-07.txt

"Les Ginsberg (ginsberg)" <> Fri, 12 January 2018 18:31 UTC

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From: "Les Ginsberg (ginsberg)" <>
To: Dino Farinacci <>
CC: "" <>, "" <>, "" <>, "" <>
Thread-Topic: [RTG-DIR} RtgDir last call review: draft-ietf-lisp-signal-free-multicast-07.txt
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Subject: Re: [lisp] [RTG-DIR} RtgDir last call review: draft-ietf-lisp-signal-free-multicast-07.txt
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Dino -

I - of course - defer to you as regards all things LISP. And if the use of RTR is already widespread, then please ignore my comment.

That said, I do not see use of "RTR" in RFC 6830. I see ITR and ETR and their TE equivalents, but I do not see "RTR".

The definition of Re-encapsulating Tunnel Router is fine. It is just that when I saw "RTR" used in the text I had to go back to the terminology section because otherwise I thought you were just talking about a "Router".



> -----Original Message-----
> From: Dino Farinacci []
> Sent: Friday, January 12, 2018 9:59 AM
> To: Les Ginsberg (ginsberg) <>
> Cc:;; draft-ietf-lisp-signal-free-
> Subject: Re: [RTG-DIR} RtgDir last call review: draft-ietf-lisp-signal-free-
> multicast-07.txt
> > The first use of LCAF (Section 2) should be expanded.
> >
> > I find the acronym "RTR" a bit unfortunate for the obvious reason that
> > it intuitively represents "just a router". I wonder if the authors
> > could
> Les, I understand your concern here. However, RTR is littered throughout
> many LISP documents as well as in product documentation and
> implementations. We have clearly defined it in the base documents and for
> any new use-case of an RTR, it is explained in the use-case documents.
> I really think it is too late. The term will continue to be used even if IETF
> changes the documents. And adding a new term could add confusion (you’d
> have to clarify everywhere that an RTR and a ReTR is the same thing).
> > consider something like "ReTR". I am sensitive to the fact that this
> > document has been around since 2014 and has undergone significant WG
> > review. I have
> RTR was introduced in a general way in RFC6830 which dates even further
> back in time. And the component has added NAT functionality, TE
> functionality, and in this document multicast functionality.
> > not attempted to track all of the email history regarding this
> > document. Perhaps this point has been considered and consensus has
> > been that the RTR acronym is the best choice. If so, feel free to disregard
> my suggestion, but as someone who read this document for the first time I
> found myself looking back for the definition of "RTR" multiple times as I read
> through the text.
> Do you believe the definition is sufficient? This is what’s in the current
> document:
>   Re-encapsulating Tunnel Router (RTR): An RTR is a router that
>    implements the re-encapsulating tunnel function detailed in Section 8
>    of the main LISP specification [RFC6830].  A LISP RTR performs packet
>    re-routing by chaining ETR and ITR functions, whereby it first
>    removes the LISP header of an ingress packet and then prepends a new
>    LISP header to an egress packet.
> Dino