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

[János Farkas <[e-mail]>]

Hi Alissa,

Thank you for the clarification.
I agree with the change you are suggesting.
I propose to make the change.

At this stage, I suggest to avoid any further change that is not necessary.

Thank you!
Janos


On 4/18/2019 6:52 PM, Black, David wrote:
>
> +1 on Alissa’s near-final comment:
>
> > […] the architecture does not actually forbid the possibility of 
> adding additional information into DetNet packets that could be used 
> as vectors for tracking/correlation.
>
> My understanding is that this is allowed by the DetNet architecture 
> even though none of the data plane designs have done so to date.  In 
> particular, I’ve seen some prior discussion of using DSCPs for to 
> identify DetNet traffic, even though that approach is not currently 
> being pursued.
>
> Thanks, --David
>
> *From:* detnet <[e-mail]> *On Behalf Of *Alissa Cooper
> *Sent:* Wednesday, April 17, 2019 9:34 AM
> *To:* János Farkas
> *Cc:* [e-mail]; [e-mail]; Lou 
> Berger; IESG; [e-mail]
> *Subject:* Re: [Detnet] Alissa Cooper's Discuss on 
> draft-ietf-detnet-architecture-11: (with DISCUSS and COMMENT)
>
> [EXTERNAL EMAIL]
>
> Hi János,
>
>
>
>     On Apr 15, 2019, at 5:08 PM, János Farkas
>     <[e-mail] <mailto:[e-mail]>> wrote:
>
>     Hi Alissa,
>
>     Please see in-line.
>
>     On 4/12/2019 7:08 PM, Alissa Cooper wrote:
>
>         Hi János,
>
>
>
>             On Mar 25, 2019, at 12:16 PM, János Farkas
>             <[e-mail]
>             <mailto:[e-mail]>> wrote:
>
>             Hi Alissa,
>
>             We believe that we have addressed your comments in the
>             most recent revision:
>             https://tools.ietf.org/html/draft-ietf-detnet-architecture-12.
>             (https://mailarchive.ietf.org/arch/msg/detnet/utVL9ZVGcOeGtRIASRFx5WT_ErM)
>
>             Please let us know what else you would like to see done
>             before you clear your DISCUSS.
>
>             I/we would be happy to meet with you this week if there is
>             anything you would like to discuss.
>
>             Regards,
>             Janos
>
>             On 2/26/2019 2:20 PM, János Farkas wrote:
>
>                 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 don’t understand why this is not expected. From what I can
>         tell, the architecture allows for the use off domain- or
>         app-flow-specific IDs. These seem like a new potential vector
>         for tracking, and one that not every QoS architecture requires.
>
>     As far as I understood from below, you were happy with the change
>     to "is not expected”.
>
> “Combined with the above removals” (about flow IDs and OAM) is what I 
> said. Either the architecture allows for these things, in which case 
> one might expect them, or it doesn’t.
>
>
>
>
>     Combined that with this discussion on the related text:
>     https://mailarchive.ietf.org/arch/msg/detnet/-L_wsGPMqNEOtPMgsGYaJ30nFXk
>
>     We came to the current text:
>        DetNet provides a Quality of Service (QoS), and as such, is not
>        expected to directly raise any new privacy considerations, the
>        generic considerations for such mechanisms apply.  In particular,
>        such markings allow for an attacker to correlate flows or to select
>        particular types of flow for more detailed inspection.
>
>
>     Flow ID and associated QoS is not a new concept introduced by
>     DetNet; therefore, does not expected to raise new concerns.
>
>     What specific further changes do you suggest to this text?
>
> Given your exchange with Benjamin and the email today from Stewart, I 
> would suggest:
>
> DetNet provides a Quality of Service (QoS) mechanism, and the generic
>
>    considerations for such mechanisms apply.  In particular, such markings
>
>    allow for an attacker to correlate flows or to select particular types
>
>    of flow for more detailed inspection.
>
> My point is that the architecture does not actually forbid the 
> possibility of adding additional information into DetNet packets that 
> could be used as vectors for tracking/correlation. This change would 
> also address my concern about the OAM piece, but if you or the WG want 
> to pursue further edits regarding OAM given Greg’s mail I’m happy to 
> review.
>
> Best,
>
> Alissa
>
>
>
>
>
>         This edit also doesn’t seem to cover the potential for
>         additional privacy exposure implied by the discussion of OAM
>         in Section 4.1.1:
>
>     Thank you for making clear that this is the text you mean under
>     "novel flow IDs and OAM tags" below. It was not clear to me
>     because the architecture document does not contain either new /
>     novel   Flow ID / OAM tag.
>
>
>         "OAM can involve specific tagging added in the packets for
>         tracing implementation or
>
>            network configuration errors; traceability enables to find
>         whether a
>
>            packet is a replica, which DetNet relay node performed the
>
>            replication, and which segment was intended for the replica.
>
>
>     This text is there since:
>     https://tools.ietf.org/html/draft-finn-detnet-architecture-05.
>
>
>         Active
>
>            and hybrid OAM methods require additional bandwidth to
>         perform fault
>
>            management and performance monitoring of the DetNet
>         domain.  OAM may,
>
>            for instance, generate special test probes or add OAM
>         information
>
>            into the data packet.”
>
>     This was added based on
>     https://www.ietf.org/mail-archive/web/detnet/current/msg01577.html.
>
>     This paragraph reads to me as pretty generic text on OAM.
>
>     What specific cahnge would you like to see made to this text?
>
>     Should we, e.g., update the first sentence of the paragraph to:
>        OAM can support tracing implementation or
>        network configuration errors. Traceability enables to find
>     whether a
>        packet is a replica, which DetNet relay node performed the
>        replication, and which segment was intended for the replica.
>
>     ?
>
>     Regards,
>     János
>
>
>
>
>         Thanks,
>
>         Alissa
>
>
>
>
>                 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
>
>                 On 2/20/2019 4:39 PM, Lou Berger wrote:
>
>                     On 2/20/2019 10:25 AM, Alissa Cooper wrote:
>
>
>
>                             On Feb 20, 2019, at 7:17 AM, Lou Berger
>                             <[e-mail]
>                             <mailto:[e-mail]>> wrote:
>
>                             Hi Alissa,
>
>                             Thanks for the comments - see below.
>
>                             On 2/20/2019 9:54 AM, Alissa Cooper wrote:
>
>                                 Alissa Cooper has entered the
>                                 following ballot position for
>                                 draft-ietf-detnet-architecture-11: Discuss
>
>                                 When responding, please keep the
>                                 subject line intact and reply to all
>                                 email addresses included in the To and
>                                 CC lines. (Feel free to cut this
>                                 introductory paragraph, however.)
>
>
>                                 Please refer to
>                                 https://www.ietf.org/iesg/statement/discuss-criteria.html
>                                 for more information about IESG
>                                 DISCUSS and COMMENT positions.
>
>
>                                 The document, along with other ballot
>                                 positions, can be found here:
>                                 https://datatracker.ietf.org/doc/draft-ietf-detnet-architecture/
>
>
>
>                                 ----------------------------------------------------------------------
>                                 DISCUSS:
>                                 ----------------------------------------------------------------------
>
>                                 = 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.
>
>
>                             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.
>
>                     sounds reasonable.  Can you point to the specific
>                     offending text?
>
>                     Thanks,
>
>                     Lou
>
>
>
>
>                             Would changing to "is not expected"
>                             address your concern?
>
>                         Combined with the above removals, that would
>                         work for me.
>
>                         Thanks,
>
>                         Alissa
>
>
>
>
>                             Thanks,
>
>                             Lou
>
>
>
>
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