North American Network Operators Group|
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RE: Why do some ISP's have bandwidth quotas?
Joe Greco wrote: >> Technically the user can use the connection to it's maximum >> theoretical speed as much as they like, however, if an ISP has a >> quota set at 12G/month, it just means that the cost is passed along >> to them when they exceed it. > > And that seems like a bit of the handwaving. Where is it costing the > ISP more when the user exceeds 12G/month? > > Think very carefully about that before you answer. If it was arranged > that every customer of the ISP in question were to go to 100% > utilization downloading 12G on the first of the month at 12:01AM, it > seems clear to > me that you could really screw up 95th. First, the total transfer vs. 95%ile issue. I would imagine that's just a matter of keeping it simple. John Q. Broadbanduser can understand the concept of total transfer. But try explaining 95%ile to him. Or for that matter, try explaining it to the average billing wonk at your average residential ISP. As far as the 12GB cap goes, I guess it would depend on the particular economics of the ISP in question. 12GB for a small ISP in a bandwidth-starved country isn't as insignificant as you make it sound. But lets look at your more realistic second whatif: > 90GB/mo is still a relatively small amount of bandwidth. That works > out to around a quarter of a megabit on average. This is nowhere > near the "100%" situation you're discussing. And it's also a lot > higher than the 12GB/mo quota under discussion. As you say, 90GB is roughly .25Mbps on average. Of course, like you pointed out, the users actual bandwidth patterns are most likely not a straight line. 95%ile on that 90GB could be considerably higher. But let's take a conservative estimate and say that user uses .5Mbps 95%ile. And lets say this is a relatively large ISP paying $12/Mb. That user then costs that ISP $6/month in bandwidth. (I know, that's somewhat faulty logic, but how else is the ISP going to establish a cost basis?) If that user is only paying say $19.99/month for their connection, that leaves only $13.99 a month to pay for all the infrastructure to support that user, along with personnel, etc all while still trying to turn a profit. In those terms, it seems like a pretty reasonable level of service for the price. If that same user were to go direct to a carrier, they couldn't get .5Mbps for anywhere near that cost, even ignoring the cost of the last-mile local loop. And for that same price they're also probably getting email services with spam and virus filtering, 24-hr. phone support, probably a bit of web hosting space, and possibly even a "backup" dial-up connection. Andrew