[LINK] Question: volume charges

[KevinL]

On Wed, 2002-11-20 at 15:16, bscott@gtlaw.com.au wrote:

> presenting them as a flat rate.  In my view carriers, if they were honest,
> would give a separate rate for domestically sourced content and a separate
> rate again for on net content (ie content from within their own network).
> Bunded prices do nothing to discipline the market to reflect the underlying
> costs (ie give people a disincentive to download international content).

The cost to develop a system that can actually count the different
charges on traffic like that is often prohibitive.  Telstra have enough
trouble actually counting all their traffic, let alone differentiating.

Counting traffic in an ISP environment is a lot harder than you might
think.  For instance (to take a case from an ISP I used to work at), say
I have two customers, and I want to count the traffic being delivered to
each of them separately.  I find out what IP numbers they're using, and
I count the traffic to each IP number, and bill them accordingly.

Now what happens if my two users get links to each other, and start
dragging traffic down through each other?  Do I still bill customer A
even though I'm sending the traffic down customer B's link, and he's
on-sending (and quite possibly charging) to customer A?

(Any business level call you might make about this may well be wrong -
customer B is a wholesaler in their own right, who has links to a number
of places including myself and my own upstream, and is essentially in
competition with me.  Changing the routing like this can happen on the
fly, so counting and allocating has to happen in essentially real-time
(and the charge per Mb for the traffic changes depending on which link
it goes down).  The customers, on top of all of that, probably expect to
be billed for the traffic that goes down their link, not the traffic
that enters my network destined for them - rightly so, those are two
different things).

That was one challenge among many (it was a challenge because
scalability and differentiation required that readings be taken
somewhere other than at the customer's interface, thus the customer IP's
were the identifying factor, before you solve it by reading direct off
the customer's pipe).  The 'net is not designed to be cleanly counted. 
It's doable, but doing it properly on any moderately complex network
requires a high investment of tech time, both initially and ongoing.

And customers aren't willing to pay for that.  They want cheap, and they
want good quality - they most certainly do _not_ want to have to lookup
a table to figure out whether they're traffic's going to cost them 5c,
10c or be free, every time they access a site.

The one differentiation that is worth doing, imnsho, is free local
traffic.  That one's a bit easier, because you can often place the
counters appropriately, but there's still some gotchyas - particularly
when you start trying to subtract one amount of traffic read in one
place, from another amount read somewhere else.

Many ISP's already do this - retaining local mirrors simply to cut their
own bandwidth requirements.

> There are programs which will monitor the amount of data you download
> (they're hard to find, as they're mostly geared to time based charging).
> However you need to keep in mind that for every 8 bits you receive 11 bits
> are sent (for error checking and redundancy). You raise some interesting
> points about where the data should be measured and who pays for bad
> packets.

It's more complex than that.  The traffic count you're measuring is not
the same as the count on any given other link between you and the source
- the size of encapsulation of data changes based on the physical media,
and upstreams are usually charging inclusive of this encapsulation.  The
difference can be up to about 25% or so.  Most of those programs don't
include any physical media encapsulation, to speak of - they're giving
you a reading once the host has the data.  _May_ work in a consumer
dialup setting, is likely to be wrong elsewhere.

> The final thing about volume based charges is that while charges remain
> bundled and there are restrictons on home servers it is my view that the
> growth of broadband in Aus will be unnecessarily limited.  Everyone but
> everyone wants to communicate with their peers, but models which attempt to
> encourage this have been soundly ignored or actively stymied by carriers.

One of the funny ones which comes up periodically is that marketing
people, by and large, dislike the idea that a business with two offices
in a given city might get two low-rental-per-month accounts and do
automated backups + VOIP between the two offices - basically run the
pipes flat out and pay nothing for the privilege.  Certainly, that sort
of model is cheaper than buying dedicated lines between the offices off
Telstra, if you can do it...

KJL