[no subject]

> A customer with a relatively random usage (user's surfing the
> web) couldn't do this, but a user transfering batch files on a
> set schedule may see dramatic differences in their bill.

If the user doesn't want to pay for line rate for big batch transfers
then there are a lot better ways to rate-limit their usage in those
cases than to turn their router interfaces on and off at 50% the ISP's
rate sampling window.  One way or another though the user has to move N
bytes in T seconds and whether they move it in short bursts or at a
constant average rate half the speed of the bursts is irrelevant.

Either way the ISP doesn't care -- the user pays for the average peak
*bandwidth* over a given sample time that they're actually using!
 
BTW, with the price of disks these days it's not too difficult for any
ISP to use even a 5-second sample period.  That's just over 0.5 million
samples per customer per month, and in a well packed data file that's
just 6MB per customer per month even if you keep a timestamp and both
the in and out Counter32 values!  Spread the data out a bit with field
separators and you're still only looking at less than 7MB/customer/month
in the worst of cases.  Tell me again how the customer's going to beat
the system and get more value than I bill him for?  Not only that but
it's now enough of a bother that the customer probably won't bother
trying to collect his own samples and match my calculations!  :-)

-- 
                                                        Greg A. Woods

+1 416 218-0098      VE3TCP      <gwoods () acm org>     <woods () robohack ca>
Planix, Inc. <woods () planix com>;   Secrets of the Weird <woods () weird com>