Re: [mpls] Genart last call review of draft-ietf-mpls-sr-over-ip-02

"Adrian Farrel" <> Tue, 26 February 2019 15:11 UTC

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From: Adrian Farrel <>
To: 'Robert Sparks' <>,
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Subject: Re: [mpls] Genart last call review of draft-ietf-mpls-sr-over-ip-02
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Hey Robert,

Some detailed responses.

The revision will be posted when the authors have signed off.


> The 2nd sentence of the introduction is complex. It should
> be easy to simplify.


> It would help to place the reference to draft-ietf-mpls-spring-entropy
> label at "If encoding of entropy is desired". (Or if some other reference
> is better, use that)

Used RFC 6790.

> In that same paragraph, something is wrong at "make use of entropy
> label mechanism." Should that be "the entropy label mechanism"?

Yes. I have done some gardening.

> SRGB is used without expansion.


> Where is "the lower bound" of an SRGB defined? The string "lower bound"
> doesn't occur in either of the routing-extensions drafts referenced where
> SRGB is first used.

The concept of an SRGB is defined in RFC 8402. I've added a reference to this at the first use of 'SRGB'.

> Section 3.1 is about ostensibly about constructing a FIB entry, but its
> last step is sending a packet.

Yes. Overly enthusiastic engineers! 😊
I have jiggled the text so that the last couple of points are about how the FIB is used.

> The first sentence in section 3.2 is more complex than it needs to be. It
> should be easy to simplify.


> It would be nice if you could make the differences between the routers in
> figures 3 and 4 visually apparent rather than relying on text to explain the
> difference. Something like (view in a fixed width font):

We looked at this, but decided against. If we adopt some kind of notation, we will still need to explain it in the text, and the explanation will only complicate things.

> At the first paragraph on page 9: s/and then process/and then processes/