Re: 90 IPv6 sub-TLA allocations made, ipv6-wg ipv6-wg@localhost

[Joao Luis Silva Damas <]

Hi,

I think the RIR staff working on the new policy draft understand the 
issue. I believe the new draft will reflect this by moving away from 
a fixed percentage to using the huitema/durand ratio which is meant 
to give a consistent view of space utilization when using variable 
levels of hierarchy.

Joao Damas
RIPE NCC

At 17:27 +0100 14/8/01, Peter Willis wrote:
> Colleagues,
>
> I've just done some calculations that shows the maximum theoritical
> utilisation that can be achieved is 75% whilst maintaining the minimum size of
> routing table. That is if you take a large number of subnets, each subnet
>  containing a random number of hosts, and assign to each subnet the nearest
>  power of 2 larger than the number of hosts, the utilisation you get is 75%.
>
> This is a 75% utilisation per level of network hierarchy.
>
> So if we assume 3 levels of network hierarchy and each level doing perfect
>  routing aggregation and perfect address allocation we will get an overall
>   utilisation of
>  0.75^3 = 0.422 == 42% overall utilisation for the TLA.
>
> I'd like to bet that if we have a network with enough hosts to justify 64 bits
> of address space it'll also be large enough to require more than 3 levels of
> network hierarchy. Any requirements to get high address space utilisation out
> of IPv6 can simply be demonstrated to lack scaling qualities.
>
> Regards,
>
>
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> Peter Willis		            | E-mail: peter.j.willis@localhost
> IP Technology Strategist            | Phone:  01473 645178 Fax: 01473 644506
> BTexact Technologies CTO            |
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