Of course bandwidth != subnet mask. He should give them
whatever IP's
they demonstrate a need for in the next three months. Determining and
justifying that
need has nothing to do with how over (or under) subscribed their
bandwidth is.
Let us not forget what some salespersons will promise to potential large
bandwidth customers. An OC-3 POS customer, for example, can expect many
many /24s. One may say "They should go to ARIN", but alas, they would have
to pay another $2500 on top of the $1 million+ they are paying for transit.
<8{}
It is surprising how much a salesperson will "sell" to get the commission on
a 5 year OC-3 contract, forget about OC-12/48...
So, in some cases, like it or not, bandwidth sold is proportional to IP
addresses.
chris
ISPs should be following rfc 2050. It doesn't matter if they have
a dedicated 56k or an OC-192. Customers can and should expect to have their
space needs met as per their needs. These guidelines are not that draconian:
Although topological issues may make exceptions necessary, the basic
criteria that should be met to receive network numbers are listed
below:
25% immediate utilization rate
50% utilization rate within 1 year
The utilization rate above is to be used as a guideline, there may be
be occasions when the 1 year rate does not fall exactly in this
range. Organizations must exhibit a high confidence level in its 1
year utilization rate and supply documentation to justify the level
of confidence.
Austin
IIRC, Sprint wanted us to show 80% utilization within 3 months(!), citing
ARIN guidelines...
James Smallacombe PlantageNet, Inc. CEO and Janitor
up@3.am http://3.am
James:
That's for allocation to ISP's. The RFC refered to end user utilization
of the address space (see http://www.arin.net/regserv/ip-assignment.html).
I've seen some ISP's incorrectly quote the 80% utilization to customers
and expect them to achieve that before assigning them more IP address
space.
Chuck
The 80% utilization rule makes sense for ADDITIONAL allocations, where an
end user already has space but needs more. Of course, exceptions can be
made for large deployments (customer has 150 hosts on a single /24, but
needs two more for a 400-host data center, etc.)
For initial allocations, the 50% rule makes the most sense, IMHO.
-Chris
Please note that the RFC2050 reference to 25% and 50% is for end user
address space, while the 80% refers the ISP's level of assignment of their
allocated address space. I was refering to the confusion some ISP's
exhibit in requesting %80 utilization by end users prior to additional
assignments.
Chuck
It's not really a question of what makes sense, it's what you need to do
to keep ARIN happy. As an ISP, if you only apply the 25% / 50% rule to
your customers, how are you supposed to demonstrate 80% utilization to
ARIN when requesting any kind of allocation?
If you've handed out a whole bunch of /24 - /29 subnets to your customers
and they are compliant with RFC2050, this could well result in a situation
where you've depleted nearly all of your address space, yet are nowhere
near 80% utilization or your, say, /21 from your upstream. Is ARIN going
to allocate you a /20?