Subject: [Rtg-dt-encap-considerations] Added Hardware Friendly to Dallas slides

From: Erik Nordmark <[email-masked]>
Date: Tue, 10 Mar 2015 18:20:30 -0700

See
https://docs.google.com/a/aristanetworks.com/presentation/d/1r_LpKB0tV8VJVJx-t3h3NJagRCtIxqFXS8JesV9BCOo/edit?usp=sharing

First question is whether we agree on this summary (I did it from memory)
Second question is whether we should add the Hardware Friendly slide to 
the NVO3 slides for this Friday's presentation?
It might raise some discussion.

    Erik

---

From: "Larry Kreeger (kreeger)" <[email-masked]>
Date: Wed, 11 Mar 2015 22:47:34 +0000

Hi Erik,

Here are my comments on the slides.  I don't know if the hardware friendly
slide will stimulate more discussion than several other points in these
slides, so I don't see why not to have it.

Slide 7: I'm not sure what the bullet "Perhaps optional OAM info modified
along path?" means.  Also, SFC allows not only the service path info to be
carried (and modified), but the service metadata may also be modified.

Slide 9: It isn't clear to me whether limiting the source port entropy to
only use the ephemeral port range is required.  I think in many cases it
will be fine to use all 16 bits of source port.

Slide 13: The bullet "Use some 'discard' next header value?" is one
option, but it eliminates the possibility of carrying a payload snippet
before the OAM message.  The other option is an explicit OAM bit (which
several headers have).

Slide 18: Loose -> Lose

Slide 24: Why is there a question mark after "WG document"?  We already
have a document.  Maybe this is to remind you to put the draft name?

 - Larry

On 3/10/15 6:20 PM, "Erik Nordmark" <[email-masked]> wrote:

>
>See
>https://docs.google.com/a/aristanetworks.com/presentation/d/1r_LpKB0tV8VJV
>Jx-t3h3NJagRCtIxqFXS8JesV9BCOo/edit?usp=sharing
>
>_______________________________________________
>Rtg-dt-encap-considerations mailing list
>[email-masked]
>https://www.ietf.org/mailman/listinfo/rtg-dt-encap-considerations

---

From: Erik Nordmark <[email-masked]>
Date: Wed, 11 Mar 2015 16:18:27 -0700

> slides, so I don't see why not to have it.
OK, I've added the slide to the NVO3 set for now.
> along path?" means.
This was a vague reference to timestamps etc for OAM purposes. I've 
reworded it to be more specific.
> Also, SFC allows not only the service path info to be
Is " *Service meta-data may be modified by service functions" a correct 
state*ment?**
> will be fine to use all 16 bits of source port.
The document doesn't even specify exactly why, but has some more text.
If there is some middlebox, it might look at the UDP source port. For 
instance, UDP source ports used by known insecure protocols might be 
blocked by a firewall. If all 16 bits are used that means some flows 
would get blocked. But in other deployments all bits can be used.

How about I have the slide say ">=14 bits" and we can talk to this point?
> before the OAM message.  The other option is an explicit OAM bit (which
I've reworded as
*Use some “discard” next header value, or OAM bit?

*Note that I'm not sure the discussed OAM bit means the same to everybody.**
> Slide 18: Loose -> Lose
Fixed.
> have a document.  Maybe this is to remind you to put the draft name?
The DT output is a personal document. I don't know (and haven't asked 
Alia) whether her intent was to have the RTGWG pick this up as a WG 
document and review it. Hence asking the question.

I made it a bit more clear:
*RTGWG WG document? Or somewhere else?

*Thanks for your review.

Erik

**

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From: "Larry Kreeger (kreeger)" <[email-masked]>
Date: Thu, 12 Mar 2015 00:57:48 +0000

>Is " *Service meta-data may be modified by service functions" a correct

Yes.

>would get blocked. But in other deployments all bits can be used.

Yes, exactly.

>How about I have the slide say ">=14 bits" and we can talk to this point?

Sure.

>*Use some ³discard² next header value, or OAM bit?

OK.

>*Note that I'm not sure the discussed OAM bit means the same to

Hmmm.  Well it would be good to find out then :-)

>*RTGWG WG document? Or somewhere else?

My impression was that Alia commissioned this work (As a Routing Area AD)
- asking us to write a document...which meant that it was part of the
RTGWG.  Clarification from Alia before these slides are presented would be
good.

---

From: Alia Atlas <[email-masked]>
Date: Wed, 11 Mar 2015 23:06:47 -0400

The draft is being discussed in RTGWG.  It's up to the chairs & WG to
decide about
adoption.  I'd be surprised if that doesn't happen, but if it did, we could
discuss why.

Thanks for the hard work,
Alia