Subject: [Detnet] Alissa Cooper's Discuss on draft-ietf-detnet-architecture-11: (with DISCUSS and COMMENT)

From: Alissa Cooper <[email-masked]>
Date: Wed, 20 Feb 2019 06:54:37 -0800

Alissa Cooper has entered the following ballot position for
draft-ietf-detnet-architecture-11: Discuss

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for more information about IESG DISCUSS and COMMENT positions.

The document, along with other ballot positions, can be found here:
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DISCUSS:
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= Section 6 =

"DetNet is provides a Quality of Service (QoS), and as such, does not
   directly raise any new privacy considerations."

This seems like a false statement given the possibility that DetNet may require
novel flow IDs and OAM tags that create additional identification and
correlation risk beyond existing fields used to support QoS today.

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COMMENT:
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I support Benjamin's DISCUSS.

I agree with others that this document should be informational.

= Section 3.1 =

"There are, of course, simpler methods available (and employed, today)
   to achieve levels of latency and packet loss that are satisfactory
   for many applications."

I think this paragraph would make more sense if it said "specific levels of
latency and packet loss for particular applications." A lot of applications
have satisfactory performance without any of the methods/techniques described.

"Prioritization and over-provisioning is one
   such technique."

It seems these are two techniques, not one.

= Section 3.2.1.2 =

s/sensitive/time-sensitive/

I can't parse this sentence:

'In general, users are encouraged to use, instead of, "do this when you
   get the packet," a combination of:

   o  Sub-microsecond time synchronization among all source and
      destination end systems, and

   o  Time-of-execution fields in the application packets.'

= Section 3.2.2.2 =

s/ Either of these functions/ Any of these functions/

"Providing sequencing information to the packets of a DetNet
      compound flow.  This may be done by adding a sequence number or
      time stamp as part of DetNet, or may be inherent in the packet,
      e.g., in a higher layer protocol, or associated to other physical
      properties such as the precise time (and radio channel) of
      reception of the packet."

How do multiple connected DetNet nodes know which fields they are supposed to
use as the packet sequence number?

= Section 3.3.1 =

"the highest-priority non-DetNet packet is also ensured a worst-case latency."
--> Did you mean "ensured less than or equal to a worst-case latency"?

= Section 4.3.2 =

If applications need to be altered to be run over DetNet, or if they need to be
DetNet-aware, it would be useful to state that explicitly up front somewhere in
this document. This is sort of implied in this section but it's not clear.

= Section 6 =

"However, the requirement for every (or almost every) node along the
   path of a DetNet flow to identify DetNet flows may present an
   additional attack surface for privacy, should the DetNet paradigm be
   found useful in broader environments."

I'm not sure what is meant by "broader environments." Is the implication that
flow identification doesn't present a privacy risk within a single
administrative domain? I don't think that is always true.

---

From: Lou Berger <[email-masked]>
Date: Wed, 20 Feb 2019 10:17:14 -0500

Hi Alissa,

Thanks for the comments - see below.

> https://datatracker.ietf.org/doc/draft-ietf-detnet-architecture/

Based on the other work in the WG, I think "is not expected" is more 
accurate than "does not". This is based on the WG solutions for the 
DetNet data plane using existing IP (v4 or 6) headers or MPLS labels for 
flow identification.

Would changing to "is not expected" address your concern?

Thanks,

Lou

---

From: Alissa Cooper <[email-masked]>
Date: Wed, 20 Feb 2019 07:25:21 -0800

> On Feb 20, 2019, at 7:17 AM, Lou Berger <[email-masked]> wrote:
> 
> Hi Alissa,
> 
> Based on the other work in the WG, I think "is not expected" is more accurate than "does not". This is based on the WG solutions for the DetNet data plane using existing IP (v4 or 6) headers or MPLS labels for flow identification.

If that is the case then the references to new flow IDs and OAM tags should be removed from the architecture.

> Would changing to "is not expected" address your concern?

Combined with the above removals, that would work for me.

Thanks,
Alissa

---

From: Lou Berger <[email-masked]>
Date: Wed, 20 Feb 2019 10:39:40 -0500

On 2/20/2019 10:25 AM, Alissa Cooper wrote:
>
>
>> On Feb 20, 2019, at 7:17 AM, Lou Berger <[email-masked] 
>> <mailto:[email-masked]>> wrote:
>>
>> Hi Alissa,
>>
>>> Please refer to 
>>> https://www.ietf.org/iesg/statement/discuss-criteria.html
>> DetNet data plane using existing IP (v4 or 6) headers or MPLS labels 
>> for flow identification.
>

sounds reasonable.  Can you point to the specific offending text?

Thanks,

Lou

> _______________________________________________
> detnet mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/detnet

---

From: János Farkas <[email-masked]>
Date: Tue, 26 Feb 2019 14:20:25 +0100

Hi Alissa,

Thank you for your review!

We can replace
"DetNet is provides a Quality of Service (QoS), and as such, does not
    directly raise any new privacy considerations."
with
"DetNet provides a Quality of Service (QoS), and as such, is not expected to
    directly raise any new privacy considerations."

I'm not sure what "references to new flow IDs and OAM tags should be 
removed"?

Could you point to the text that should be changed?

Thank you!
Janos