Allocations for "always-on" ISPs

At 12:25 06/12/00, Bruno Ciscato wrote:
>With the advent of technologies like ADSL and Ethernet to the home, 
>several new ISP in Europe are starting to offer "always on" Internet access.
>The allocation strategies vary, if they give a subnet to each household 
>this is usually a /29, if they group more than one household in each 
>subnet the average IPv4 address consumption by each household can be a 
>little less.

Ahem! You mean Assignment strategy. ;) (Allocation is what RIPE NCC gives 
the LIR, Assignment is what the LIR gives to it's customer)

Why a /29? Why not a /30?

On the other hand, why not /32 assignments to a customer, just like in a 
static IP dialup where the customer uses NAT?

Alternatively, have your DSL network covered in RFC 1918 addresses and do 
DHCP addressing within that to end users.

>In any case they need a lot of addresses, i.e. a few millions.
>Can someone help me to see if what I think it would happen is correct?
>1) they request address space to RIPE, with a nicely written documentation 
>that clearly shows that they need millions of addresses
>2) nonetheless they won't receive more than a /20 to begin with

This is correct.. you need to prove that you need those millions of 
addresses first. Most DSL IP requirements currently, AFAICS, are based on 
projection figures in an unknown market. Has DSL actually taken off in a 
big a way as was predicted 6 months ago?

>3) when they have used more than 80% of this /20, and can prove 
>it,  another one will be assigned, most likely not contiguous

However if you have quickly used up this /20, I do not see why the next 
block will not be contiguous.. if according to your requirements you need 
millions of addresses then these should fill up pretty quickly.

>Is there any way to reduce the address space fragmentation due to new non 
>contiguous allocations ?

I guess you need to use up your allocated block quickly enough to allow you 
to get the next contiguous block. :)

Regards
Denesh
--
Denesh Bhabuta           Chairman, CEO and Principal Consultant
Cyberstrider Limited                                   www.cyberstrider.net
  Internet and E-Commerce: Strategy, Consultancy and Solutions