Analysis of the future exhaustion of the IPv4 Central pool (Archive)


1) Analysis of the situation

To answer the questions raised above in the context of AfriNIC, we have chosen to analyze the allocation of IPv4 addresses by AfriNIC, to make projections on the final exhaustion of the AfriNIC pool following that of IANA, and to prepare to manage this predicament.

For this we have analyzed allocations made from the prefix 41/8 allocated to AfriNIC in April 2005 by IANA and used since February 1st 2006. We have analyzed allocations over a period of 12 months (February 1st 2006 on February 1st 2007), to determine the rate of consumption and make projections (Figure 1).

Figure 1: Number of IP addresses allocated from January 1st 2006 to February 1st 2007

In order to study the model used to analyze the allocations, we represented the data in a logarithmic scale (Figure 2). The period from April 9th 2006 to November 1st 2006 (211 days) shows a linear behavior indicating an exponential growth.

Figure 2: Number of IP addresses allocated from 41/8 (logs-scale format)

The instantaneous growth rate of allocations derived from the formula X (t) =X0ekt is of 0.29 %. The rest of the graph shows a similar behavior. A way of modeling the global evolution is to extend the exponential model in the remaining period (from November 2nd 2006 till February 1st 2007), 302 days in total.

Figure 3 represents the graphs of real data and that of the data obtained with our model. The result on February 1st 2007 of both graphs reassures us on the applicability of our model and we can use it to make projections on the following dates:

  1. Date of qualification for a new /8 from IANA (50 % of utilization of the actual block), 
  2. Date of exhaustion of the 41/8 block

As mentioned at the beginning, we first study the hypothesis of the constancy of conditions and actual rates of allocation. The model shows that AfriNIC will be at 50 % utilization of the 41/8 block, (8,388,608 IP addresses) at around April 22nd 2008 (after about 2 years and 2 months), and this is the date at which AfriNIC will qualify to receive a new /8 from IANA. See graph of Figure 4.

Figure 3: Exponential Model of Number of IP addresses allocated from 41/8


Figure 4: Projected Number of IP addresses allocated from 41/8 (up to 50%)

By taking a fragmentation rate of 10 % in the allocation (unallocated addresses), AfriNIC will exhaust the pool (after an allocation of 15,099,494.4) by November 11th 2008, that is after 2 years 9 months.

Figure 6: Projection of the exhaustion of the actual pool

AfriNIC should request for a new /8 from IANA by April 22nd 2008 as the IANA pool should be able to meet this request. The new block will be operational by November 11th 2008. By January 11th 2011, AfriNIC should also request a new /8 which can also be obtained. The new block will be effective on August 11th 2011 and will be exhausted by April 11th 2014. This is the situation if the actual rate of utilization is maintained and that everything works as predicted on the IANA pool.

But, what will it look like in reality?


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