Re: [HAM-AG] [IPv6] Request for feedback: draft-evan-amateur-radio-ipv6

I agree that not all of the world's ham operators are going to be using
IPv6 at the same time, Still, I feel that the draft is incomplete in an
essential way without, perhaps in the Security Considerations section,
saying SOMETHING about the probability of collision. I myself was a bit
surprised that the probability was as high as 1 in 23K but given the
birthday paradox, I guess I should have expected something like that. You
could say something about the assumptions involved, the possible growth of
the ham population, etc. You could improve things a bit by suggesting use
of a random ID in the 1-15 range.

Perhaps you should also include a probability of collision assuming only
1,000,000 hams online. That would be

1 - e**(( - 10**6)*(10**6 - 1)/(2*(2**60)))

which is only about 1 in 2.3 million.

I guess there really isn't a problem unless they have the same prefix so
the only operational problem is if the same site has a collision which
seems almost vanishingly small (i.e., probably just a likely to occur, if
not more so, due to software bugs, someone typo'ing their call sign, etc.,
than due to actual hash collision).

Thanks,
Donald
===============================
 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
 2386 Panoramic Circle, Apopka, FL 32703 USA
 d3e3e3@gmail.com

On Wed, Feb 15, 2023 at 9:11 AM Evan Pratten <ewpratten@gmail.com> wrote:

> Donald,
>
> I largely agree with Jeffrey. I don't imagine every radio operator
> would be in a network all at once so in theory it shouldn't be a
> problem. BUT I think it is a good idea to plan for such a thing
> anyways. I wondered about the drawbacks of truncating SHA256. Do you
> have a recommendation for a better choice of hashing algorithm for
> this use case?
>
> Callsigns are almost always going to be shorter than any string they
> hash into, plus the character set is just ASCII. There must be
> something well suited for this.
>
> On Wed, Feb 15, 2023 at 7:51 AM Jeffrey (Zhaohui) Zhang
> <zzhang@juniper.net> wrote:
> >
> > Hi Donald,
> >
> >
> >
> > The number of stations connecting to this network would be limited,
> though. Does that matter?
> >
> >
> >
> > Hi Evan,
> >
> >
> >
> > I am a new ham (about four years) and have never tried AR-based IP
> network. Can you share some pointers?
> >
> >
> >
> > Thanks.
> >
> > Jeffrey KC1LWE
> >
> >
> >
> >
> >
> > Juniper Business Use Only
> >
> > From: HAM-AG <ham-ag-bounces@ietf.org> On Behalf Of Donald Eastlake
> > Sent: Tuesday, February 14, 2023 10:23 PM
> > To: Evan Pratten <ewpratten@gmail.com>
> > Cc: draft-evan-amateur-radio-ipv6@ietf.org; ham-ag@ietf.org
> > Subject: Re: [HAM-AG] [IPv6] Request for feedback:
> draft-evan-amateur-radio-ipv6
> >
> >
> >
> > [External Email. Be cautious of content]
> >
> >
> >
> > Hi,
> >
> >
> >
> > An interesting simple draft.
> >
> >
> >
> > I think it needs an estimate of the probability of duplication. There
> are about 10,000,000 ham radio operators in the world. So I think the
> probability of a conflict if they were all using this draft would be
> >
> >
> >
> > 1 - e**(( - 10**7)*(10**7 - 1)/(2*(2**60)))
> >
> >
> >
> > or approximately  1 in 23,057.
> >
> >
> >
> > Thanks,
> > Donald
> > ===============================
> >  Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
> >  2386 Panoramic Circle, Apopka, FL 32703 USA
> >  d3e3e3@gmail.com
> >
> >
> >
> >
> >
> > On Tue, Feb 14, 2023 at 3:43 PM Evan Pratten <ewpratten@gmail.com>
> wrote:
> >
> > Hello all,
> >
> > I have been working on my first I-D, an alternate method for
> > generating IPv6 IIDs from amateur radio callsigns.
> >
> > After receiving good feedback from a small handful of people, I feel
> > now is the time to open this up to comments from the working groups.
> >
> > Please send along any comments, suggestions, and questions you may have.
> >
> > A Method for Deriving Stable IPv6 Interface Identifiers from Amateur
> > Radio Callsigns:
> > https://datatracker.ietf.org/doc/draft-evan-amateur-radio-ipv6/
> >
> > Thanks in advance for the feedback,
> >  - Evan
> >
> > ---
> > Evan Pratten (VA3ZZA)
> > https://ewpratten.com
> >
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