North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: Why do some ISP's have bandwidth quotas?

  • From: Joe Greco
  • Date: Fri Oct 05 12:21:33 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.


> 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 - Network Services - Milwaukee, WI -
"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.