Why do some ISP's have bandwidth quotas?
Joe Greco
jgreco at ns.sol.net
Fri Oct 5 15:58:12 UTC 2007
> > Now, ISP economics pretty much require that some amount of overcommit
> > will happen. However, if you have a 12GB quota, that works out to
> > around 36 kilobits/sec average. Assuming the ISP is selling 10Mbps
> > connections (and bearing in mind that ADSL2 can certainly go more than
> > that), what that's saying is that the average user can use 1/278th of
> > their connection. I would imagine that the overcommit rate is much
> > higher than that.
>
> I don't think that things should be measured like this. Throughput !=
> bandwidth.
No, but it gives some rational way to look at it, as long as we all realize
what we're talking about. The other ways I've seen it discussed mostly
involve a lot of handwaving.
> 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.
> > Note: I'm assuming the quota is monthly, as it seems to be for most
> > AU ISP's I've looked at, for example:
>
> Yes most are monthly based on GB.
>
> > capacity is being stifled by ISP's that are stuck back
> > in speeds (and policies) appropriate for the year 2000.
>
> Imagine a case (even in the largest of ISP's), where there are no
> quotas, and everyone has a 10Mbps connection.
I'm imagining it. I've already stated that it's a problem.
> I don't think there is an ISP in existence that has the infrastructure
> capacity to carry all of their clients using all of the connections
> simultaneously at full speed for long extended periods.
I'll go so far as to say that there's no real ISP in existence that
could support it for any period.
> As bandwidth and throughput increases, so does the strain on the
> networks that are upstream from the client.
Obviously.
> Unless someone pays for the continuously growing data transfers, then
> your 6Mbps ADSL connection is fantastic, until you transit across the
> ISP's network who can't afford to upgrade the infrastructure because
> clients think they are being ripped off for paying 'extra'.
>
> Now, at your $34/month for your resi ADSL connection, the clients call
> the ISP and complain about slow speeds, but when you advise that they
> have downloaded 90GB of movies last month and they must pay for it, they
> wont. Everyone wants it cheaper and cheaper, but yet expect things to
> work 100% of the time, and at 100% at maximum advertised capacity. My
> favorites are the clients who call the helpdesk and state "I'm trying to
> run a business here" (on their residential ADSL connection).
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.
> > What are we missing out on because ISP's are more interested in keeping
> > bandwidth use low?
>
> I don't think anyone wants to keep bandwidth use low, it's just in order
> to continue to allow bandwidth consumption to grow, someone needs to pay
> for it.
How about the ISP? Surely their costs are going down. Certainly I know
that our wholesale bandwidth costs have dropped orders of magnitude in
the last ~decade or so. Equipment does occasionally need to be replaced.
I've got a nice pair of Ascend GRF400's out in the garage that cost $65K-
$80K each when originally purchased. They'd be lucky to pull any number
of dollars these days. It's a planned expense. As for physical plant,
I'd imagine that a large amount of that is also a planned expense, and is
being paid down (or already paid off), so arguing that this is somewhere
that a lot of extra expense will exist is probably silly too.
> > What fantastic new technologies haven't been developed
> > because they were deemed impractical given the state of the Internet?
>
> Backbone connections worth $34/month, and infrastructure gear that
> upgrades itself at no cost.
Hint: that money you're collecting from your customers isn't all profit.
... JG
--
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.
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