Re: 90 IPv6 sub-TLA allocations made
- Date: Tue, 14 Aug 2001 17:27:02 +0100
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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