Re: WG ACTION: 2 weeks to discuss [LL66] Additional statistical example

Stuart - for my own understanding, can you explain the computation you made
for your statistical example?

- Ralph


At 01:20 AM 5/5/2004 +0200, Erik Guttman wrote:
>Please post discussion of this issue to the mailing list over the next two 
>weeks
>ending May 18, 2004.  In order to accept this issued, we will need a strong WG
>consensus given that this is very late in the process.
>
>Please see http://www.drizzle.org/~aboba/ZEROCONF/issues.html for a list of
>current issues and their status.
>
>[LL66]
>
>Description of Issue:           Additional statistical example
>Submitter Name:                 Stuart Cheshire
>Submitter Email Address:        [email protected]
>Date first submitted:           04 May 04
>Reference:
>Comment Type ['t'ech|'e'dit]:   t
>Prio ['S' Must|1 should|2 may]: 1
>Section:                        1.3
>Rationale/Explanation:
>Lengthy Description:
>
>>    When these address conflicts are detected, the subsequent forced
>>    reconfiguration may be disruptive, causing TCP connections to be
>>    broken. However, it is expected that such disruptions will be rare.
>>    It should be relatively uncommon for networks to be joined while
>>    hosts on those networks are active. Also, 65024 addresses are
>>    available for IPv4 Link-Local use, so even when two small networks
>>    are joined, the chance of collision for any given host is fairly
>>    small.
>
>A specific example with numbers: If two 100-host networks are joined,
>there's still a better than 75% chance that not a single host on either
>network will have to select a new address.
>
>[Erik]
>
>There has been no demand in successive reviews for further example.
>
>[Stuart]
>
>I calculated specific numbers to substantiate the previously vague
>assertion.
>
>I believe concrete facts are more informative than vagueness.
>
>[Erik]
>
>Thanks for the numbers.  My point is that we need to publish this
>document with as few changes as possible.  This is not an editorial
>change.  In my opinion 'fact' assertions generate a lot of debate.
>
>Requested Change:
>
>Add to section 1.3
>
>    This specification is intended for use with small ad-hoc networks - a
>    single link containing only a few hosts. Although 65024 IPv4 Link-
>    Local addresses are available in principle, attempting to use all
>    those addresses on a single link would result a high probability of
>    an address conflict, requiring a host to take an inordinate amount of
>    time to find an available address.
>
>becomes
>
>    This specification is intended for use with small ad-hoc networks - a
>    single link containing only a few hosts. Although 65024 IPv4 Link-
>    Local addresses are available in principle, attempting to use all
>    those addresses on a single link would result a high probability of
>    an address conflict, requiring a host to take an inordinate amount of
>    time to find an available address.
>
>    If two 100-host networks are joined,
>    there's still a better than 75% chance that not a single host on either
>    network will have to select a new address.