[ppml] Policy Proposal 2007-16: Ipv4 Soft Landing - a simulationanalysis

David Conrad drc at virtualized.org
Thu Jan 31 20:21:03 EST 2008


On Jan 31, 2008, at 3:22 PM, Geoff Huston wrote:
> The key assumptions I've made are:
> 1. For requests for additional IPv4 address space the requestor has
> fully utilized their existing holdings at the point of the additional
> allocation of address space.
> 2. The distribution of new requestors who are requesting initial
> allocations and requestors wishing a further allocation are largely
> unchanged from that of the average of the past three years
> 3. That the demand model is uniformly spread across the year.
> 4. That the distribution of size of address requests is unchanged from
> that of the average of the past three years.
> 5. That the unadvertised pool of addresses has the same factors acting
> on it that have been visible in the past 3 years - i.e. no change in
> policies here.

Would you agree that an additional assumption you make is:

6. Address utilization efficiency is unchanged.

Implicit in Soft Landing is the assumption that there is non-trivial  
inefficiency in the use of allocated address space, e.g., use of  
public address space for infrastructure that could be numbered with  
private space, fixed size assignments to customers based on pricing  
tiers, unused but unrecovered assignments, etc.

The point of Soft Landing was to gradually and (somewhat) predictably  
increase the administrative costs of obtaining additional IPv4 address  
space as a means to encourage greater IPv4 utilization efficiency and/ 
or migration to IPv6.  If you make the assumption that the staged  
increases in administrative costs would have the desired effect, all  
bets would be off (and thus, doing models becomes a bit challenging  
since the increase in efficiency is not objectively derivable).

The alternative, of course, is for the increase in costs for obtaining  
additional IPv4 address space to go unpredictable all at once.  One  
day, you can get IPv4 space the way you used to, the next day, you're  
thrown to the vagaries of "the trading floor" (since we can't call it  
"a market" :-)).

To be very clear, the end point is the same whether or not something  
like Soft Landing is approved: unpredictable costs to obtain IPv4  
addresses and increased efficiency in its use. The question is "how do  
we want to get there?"

In any event, at this stage, I'm leaning towards abandoning Soft  
Landing unless someone wants to make the case that it is worthwhile  
continuing to pursue it...


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