nanog mailing list archives
Re: v6 subnet size for DSL & leased line customers
From: Owen DeLong <owen () delong com>
Date: Mon, 24 Dec 2007 07:24:52 -0800
"Well, you say we need to spend more money every year on address space. Right now we're paying $2,250/year for our /32, and we're able to serve 65 thousand customers. You want us to start paying $4,500/year, but Bobtells me that we're wasting a lot of our current space, and if we wereto begin allocating less space to customers [aside: /56 vs /48], that we could actually serve sixteen million users for the same cash. Is therea compelling reason that we didn't do that from the outset?"
Right... Let's look at this in detail: /48 per customer == 65,536 customers at $2,250 == $0.03433/customer /56 per customer == 16,777,216 customers at $2,250 == $0.00013/customer So, total savings per customer is $0.0342/customer _IF_ you have 16,777,216 customers. On the other hand, sir, for those customers who need more than 256 subnets, we're running the risk of having to assign them multiple noncontiguous prefixes. Although the costof doing so is not readily apparent, each router has a limit to the number
of prefixes that can be contained in the routing table. The cost of upgrading all of our routers later probably far exceeds the $0.03 per customer that we would save. Really, in general, I think that the place to look for per-customer savings opportunities would be in places where we have a potential recovery greater than $0.03 per customer.
This discussion is getting really silly; the fact of the matter is thatthis /is/ going to happen. To pretend that it isn't is simply naive.How high are your transit&equipment bills again, and how are you exactlycharging your customers? ah, not by bandwidth usage, very logical!Perhaps end-user ISP's don't charge by bandwidth usage...
True, but, they don't, generally, charge by the address, either.Usually, they charge by the month. If you can't cover $0.03/year/ customer
for address space in your monthly fees, then, raise your monthly fee by $0.05. I'm betting your customers won't care.
I'm betting that competition will drive the boundary left without additional fees. After all, if you're only willing to dole out /64s and your competitor is handing out /56 for the same price, then all the customers that want multiple subnets are going to go to your competitor. The ones that want /48s willAs an enduser I would love to pay the little fee for IP space that theLIR (ISP in ARIN land) pays to the RIR and then simply pay for thebandwidth that I am using + a little margin so that they ISP also earnssome bucks and can do writeoffs on equipment and personnel.Sure, but that's mostly fantasyland. The average ISP is going to want to monetize the variables. You want more bandwidth, you pay more. You wantmore IP's, you pay more. This is one of the reasons some of us areconcerned about how IPv6 will /actually/ be deployed ... quite frankly,I would bet that it's a whole lot more likely that an end-user getsassigned a /64 than a /48 as the basic class of service, and charge foradditional bits. If we are lucky, we might be able to s/64/56/.I mean, yeah, it'd be great if we could mandate /48 ... but I just can'tsee it as likely to happen.
find a competitor that offers that.That's how the real world works. I remember having to repeatedly involve
senior management in rejecting requests for /24s from customers who could not justify them because our sales people at Exodus kept promising them. The sales people continuously suggested that our competitorswere offering everyone /24s and that they had to do that to win the deals.
OTOH, "Raw bandwidth communications" seems to want to charge bandwidthutilization not actually based on the bandwidth utilized, but, the number of
IP addresses routed. They are not my ISP for that reason. Different providers have different business models. Consumers will find the provider with the business model that best fits their needs. That's the way it works in the real world.
So, the point is, as engineers, let's not be completely naive. Yes, we /want/ end-users to receive a /56, maybe even a /48, but as an engineer, I'm going to assume something more pessimistic. If I'm a device designer, I can safely do that, because if I don't assume that a PD is going to be available and plan accordingly, then my device is going to work in bothcases, while the device someone who has relied on PD is going to break when it isn't available.
Assuming that PD is available is naive. However, assuming it is not isequally naive. The device must be able to function in both circumstances if possible, or, should handle the case where it can't function in a graceful
and informative manner. Owen
Current thread:
- Re: v6 subnet size for DSL & leased line customers, (continued)
- Re: v6 subnet size for DSL & leased line customers Daniel Hagerty (Dec 23)
- Re: v6 subnet size for DSL & leased line customers Mark Smith (Dec 23)
- Re: v6 subnet size for DSL & leased line customers Joe Greco (Dec 23)
- Re: v6 subnet size for DSL & leased line customers Mark Smith (Dec 23)
- Re: v6 subnet size for DSL & leased line customers Joe Greco (Dec 23)
- Re: v6 subnet size for DSL & leased line customers Mark Smith (Dec 23)
- Re: v6 subnet size for DSL & leased line customers Joe Greco (Dec 23)
- Re: v6 subnet size for DSL & leased line customers Jeroen Massar (Dec 24)
- Re: v6 subnet size for DSL & leased line customers Trent Lloyd (Dec 24)
- Re: v6 subnet size for DSL & leased line customers Joe Greco (Dec 24)
- Re: v6 subnet size for DSL & leased line customers Owen DeLong (Dec 24)
- Re: v6 subnet size for DSL & leased line customers Joe Greco (Dec 25)
- Re: v6 subnet size for DSL & leased line customers Leigh Porter (Dec 25)
- Re: v6 subnet size for DSL & leased line customers Jeroen Massar (Dec 25)
- Re: v6 subnet size for DSL & leased line customers Paul Jakma (Dec 25)
- Re: v6 subnet size for DSL & leased line customers Christopher Morrow (Dec 21)
- Re: v6 subnet size for DSL & leased line customers Florian Weimer (Dec 23)
- Re: v6 subnet size for DSL & leased line customers Chris Adams (Dec 23)
- Re: v6 subnet size for DSL & leased line customers David Barak (Dec 23)
- Re: v6 subnet size for DSL & leased line customers Mark Andrews (Dec 23)
- Re: v6 subnet size for DSL & leased line customers Joe Greco (Dec 23)