Re: [Anima] 2nd WGLC for draft-ietf-anima-constrained-join-proxy-12, ends September 20th 2022

[Michael Richardson <[e-mail]>]

Toerless Eckert <[e-mail]> wrote:
    > On Wed, Oct 12, 2022 at 07:49:06AM +0000, Esko Dijk wrote:
    >> For the stateless proxy, it is hard to determine a good rate limit number. 1% is not good because it would slow down the joining process of a genuine Pledge to a crawl. Some strategies that could work better:

    > What is the typical lowest-bitrate that you are worried about,
    > and what is the total amount of data of an enrolment process ?

Onboarding with a certificate takes around ~3kbytes of data, particularly DTLS overhead.

    > How would you deal with proxies that are on frequencies where the duty cycle
    > is limited by law. For example devices on my 868 home automation network needs to maintain
    > a 1%/hour duty cycle.

"by law" or by regulation or by protocol?
Your 868 system might be unable to complete onboarding, or maybe it will take
an hour.

    > The problem to me seems that under those regulations, badly behaving nodes
    > can force proxy and registrar into exhausting their regulatory limit as
    > well unless either proxy and/or registar do something against that.

Yes, that's true, and why we want to be able to switch onboarding on/off.

    > It almost feels as if radio networks where there are strict duty-cycle
    > limits are requring per-pledge state on the proxy if the proxy wants to
    > defend itself against the attacking pledge exhausting the proxies own
    > duty-cycle. Unless the proxy function itself stricly operates
    > independent of pledge on a cycle that is below the overal permitted
    > duty-cycle for the proxy.

Yes, if one has ram and power, a stateful proxy can do a better job of
defending the network against attacks.  A mains-powered PLC gateway between
power and 802.15.4 could/should do exactly that.
(Mind: I saw PLC systems that do Gb/s at networkX two weeks ago...)

    > Proxy operations as described in this document are not necessarily sufficient
    > to protect proxy and/or registrar against misbehaving pledges that attack
    > proxy/registar with too much data, especially when using (radio) networks
    > with regulatory limitations on the volume permitted per sender (such as
    > 1% duty-cycle per hour limitatios).

Yes.  But, let's not boil the ocean.
It's a PS.  We need to finish it so that we can deploy it so that we can
learn.  Perfect is the enemy of good enough.


--
Michael Richardson <[e-mail]>, Sandelman Software Works
 -= IPv6 IoT consulting =-