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From: Terry Lambert <terry@lambert.org>
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: single to multiple IP address mapping
Date: Mon, 14 Oct 1996 12:31:24 -0700
Organization: Me
Lines: 77
Message-ID: <3262950C.5851C774@lambert.org>
References: <53i58m$gsc@nntpd.lkg.dec.com> <53r2ag$a7@anorak.coverform.lan> <jasonsDz9zIz.FE1@netcom.com>
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E. Jason Scheck wrote:
] How could you possibly know the details of the contract that
] he has with his ISP? In particular, I've never heard of a
] "per-user" ISP license. Why should the ISP care how many
] users use a connection; they only care about bandwidth. (Yes,
] I know, I'm assuming that the world is logical; it is a fault
] of mine).
They care about address space too, or everyone would have an
assigned IP address, not that this has much to do with the
current discussion.
More realistically, ISP's overcommit their bandwidth on the
assumption (generally correct, for a one-person-per-connection
scenario) that a give connection will exhibit a certain level
of activity characteristic of a single user.
This lets them support more than 53 simultaneous modem users
with just a T1 line (1.5M/28.8K = 53.3333), which in turn lets
them charge less for a 28.8K "sparse" connection than they would
have to charge for a "committed rate" connection.
Once you get a large number of people simultaneously using all
the 28.8K connections, the number of sustainable connections
asymptotically approaches 53 for the ISP's T1.
That's why there are different prices for different rate classes,
so they can make usage assumptions.
When you use masquerading, you are invalidating the assumptions
that the ISP made to allow him to give you the pricing you were
given -- in other words, you drive up his costs.
As nice as it would be for ISP's to just "eat the cost" to make
you happy that you've found a loophole in the ISP's assumptions,
if that happens sufficiently, there will be no incentive for the
ISP to continue to give you service. He's in it for profit, and
you can be sure that if there is no profit, he won't be in it
long.
One of the big markets for management software is connection
usage tracking software to enable ISP's to find people who
violate the assumptions (and generally, the contract; if the
ISP is not naieve, he has spelled out "acceptable use").
Once these people are found, they are given the option of
switching to another (higher) rate class, or having their
service discontinued for breech of contract.
It's mildly amusing to note at this point that people using
Centrex or other DOVBS ISDN connections in California in PacBell
service areas are pretty much forcing the phone companies to
take a hard line with everyone (which is why you see non-charged
hour reduction clauses in most new ISDN tarrifs). The net result
is that no one will get to use the service for what it was
designed for because the loophole exploiters will ruin it for
everyone else.
Feel free to act as your conscience directs, but note that your
short term gain will result in long term losses for everyone
(at the very least, normal users will have to bear their share
of the usage monitoring costs to trap abusers like you, and that
will increase what they have to pay the ISP, with no increase
in benefit to themselves).
Regards,
Terry Lambert
terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.