Re: [Dots] Mirja Kühlewind's Discuss on draft-ietf-dots-requirements-18: (with DISCUSS and COMMENT)

[<[e-mail]>]

Re-,

Please see inline.

Cheers,
Med

> -----Message d'origine-----
> De : Mirja Kuehlewind (IETF) [mailto:[e-mail]]
> Envoyé : jeudi 21 février 2019 12:42
> À : Teague, Nik
> Cc : BOUCADAIR Mohamed TGI/OLN; [e-mail];
> [e-mail]; [e-mail]; The IESG; draft-ietf-dots-
> [e-mail]
> Objet : Re: Re: [Dots] Mirja Kühlewind's Discuss on draft-ietf-dots-
> requirements-18: (with DISCUSS and COMMENT)
> 
> Hi,
> 
> please see below.
> 
> > Am 21.02.2019 um 12:18 schrieb Teague, Nik <[e-mail]>:
> >
> > Hi,
> >
> >
> > On 21 Feb 2019, at 10:58, Mirja Kuehlewind (IETF) <[e-mail]>
> wrote:
> >
> >>>> 3) In SIG-006 you say:
> >>>> "      Due to the higher likelihood of packet loss during a DDoS attack,
> >>>>    DOTS servers MUST regularly send mitigation status to authorized
> >>>>    DOTS clients which have requested and been granted mitigation,
> >>>>    regardless of client requests for mitigation status."
> >>>>
> >>>> Please note that this is only true if a not-reliable transport is used.
> If a
> >>>> reliable transport is used, data is received at the application level
> without
> >>>> loss (but maybe some delay) or the connection is terminated (if loss is
> too
> >>>> high to retransmit successfully).
> >>>>
> >>>
> >>> [Med] The requirement as worded is OK.
> >>
> >> I disagree, because as I said if a reliable transport is used this is not
> true. Maybe you can adapt this sentence slightly to clarify that you probably
> had a scenario in mind where an unreliable transport is used
> >
> > The key part here is ‘packet’ vs ‘data’ - packets will be lost on congested
> links regardless of data integrity.  This may degrade connection re-
> establishment with tcp and cause data loss in an unreliable transport.
> 
> Yes, packet loss also occurs also with reliable transports and might lead to
> connection failure. However, I don’t this how this requirement is derived
> from that effect. If I use a reliable transport and my connection does not
> fail, I can be sure that the mitigation status information have been received
> correctly, so why do I need to re-send frequently then?

[Med] The text you quoted is not about "frequent retransmission" but about sending updates related to the status of a mitigation in progress. The server has to send regular notifications to update the client about the status of a mitigation. 

> 
> Mirja
> 
> 
>