I read through this, and it didn't square with my understanding in many ways.  I
ran it past one of my senior engineers and this is his response:

"Cringely clearly needs to learn some more about the subject before he spouts
technical pronouncements.  Any ISP using VPNs to limit traffic to a customer is
crazy as a loon.  Maybe they did that in the old days, but certainly not
anymore.  I'm amazed that he honestly thinks that NO ISPs in the U.S. limit
BitTorrent traffic.  It was the first sign that he's pretty clueless technically
and doesn't talk to very many ISPs."

"I do agree with him that Net Neutrality doesn't exist now, never existed in the
past, and that this will not change.  I disagree with a few other points: 1) I
don't think that the current system is "broken" or "bad", 2) comparing shaped
traffic with unshaped traffic is dumb, 3) comparing optimized BitTorrent traffic
with unoptimized is also dumb."

Jeff 


Jeff Broadwick
ImageStream
800-813-5123 x106
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf
Of Pete Davis
Sent: Monday, June 26, 2006 6:54 AM
To: [EMAIL PROTECTED]; isp-wireless@isp-wireless.com; WISPA General List
Subject: [WISPA] Net Neutrality article by Robert X. Cringely

Sorry for the cross-post. Having not really been following the whole Neutrality
Debate, this clarified some stuff for me. I hope you enjoy it.

Copied from: http://www.pbs.org/cringely/pulpit/pulpit20060622.html

June 22, 2006
Net Neutered:
Why don't they tell us ending Net Neutrality might kill BitTorrent?

By Robert X. Cringely

Last week's column was about Bill Gates' announced departure from day-to-day
management at Microsoft and a broad view of the Net Neutrality issue. We'll get
back to Microsoft next week with a much closer look at the challenges the
company faces as it ages and what I believe is a clever and counter-intuitive
plan for Redmond's future success. But this week is all about Net Neutrality,
which turns out to be a far more complex issue than we (or Congress) are being
told.

Net Neutrality is a concept being explored right now in the U.S. 
Congress, which is trying to decide whether to allow Internet Service Providers
to offer tiers of service for extra money or to essentially be prohibited from
doing so. The ISPs want the additional income and claim they are being under
compensated for their network investments, while pretty much everyone else
thinks all packets ought to be treated equally.

Last week's column pointed out how shallow are the current arguments, which
ignore many of the technical and operational realities of the Internet,
especially the fact that there have long been tiers of service and that ISPs
have probably been treating different kinds of packets differently for years and
we simply didn't know it.

One example of unequal treatment is whether packets connect from backbone to
backbone through one of the public Network Access Points
(NAPs) or through a private peering arrangement between ISPs or backbone
providers. The distinction between these two forms of interconnection is vital
because the NAPs are overloaded all the time, leading to dropped packets,
retransmissions, network congestion, and reduced effective bandwidth. Every ISP
that has a private peering agreement still has the right to use the NAPs and one
has to wonder how they decide which packets they put in the diamond lane and
which ones they make take the bus?

Virtual Private Networks are another example of how packets can be treated
differently. Most VPNs are created by ISP customers who want secure and reliable
interconnections to their corporate networks. VPNs not only encrypt content, but
to a certain extent they reserve bandwidth. But not all VPNs are created by
customers. There are some ISPs that use VPNs specifically to limit the bandwidth
of certain customers who are viewed as taking more than their fair share. My
late friend Roger Boisvert, a pioneer Japanese ISP, found that fewer than 5
percent of his customers at gol.com were using more than 70 percent of the ISP's
bandwidth, so he captured just those accounts in VPNs limited to a certain
amount of bandwidth. Since then I have heard from other ISPs who do the same.

As pointed out last week, though, there is only so much damage that an ISP can
do and most of it seems limited to Voice-over-IP (VoIP) telephone service where
latency, dropouts, and jitter are key and problematic. Since VoIP is an Internet
service customers are used to paying extra for (that, in itself, is rare), ISPs
want that money for themselves, which is the major reason why they want
permission to end Net Neutrality--if it ever really existed.

The implications of this end to Net Neutrality go far beyond VoIP, though it is
my feeling that most ISPs don't know that. These are bit schleppers, remember,
and the advantages of traffic shaping are only beginning to dawn on most of
them. The DIS-advantages are even further from being realized, though that will
start to change right here.

The key question to ask is what impact will priority service levels have on the
services that remain, those having no priority? In terms of the packets, giving
priority to VoIP ought not to have a significant impact on audio or video
downloads because those services are buffered and if they take a little longer,
well that's just the price of progress, right? Wrong. Let's look at the impact
of priority services on BitTorrent, the single greatest consumer of Internet
bandwidth.

Though e-mail and web surfing are both probably more important to Internet users
than BitTorrent, the peer-to-peer file transfer scheme uses more total Internet
bandwidth at something over 30 percent. Some ISPs absolutely hate BitTorrent and
have moved to limit its impact on their networks by controlling the amount of
bandwidth available to BitTorrent traffic. This, too, flies in the face of our
supposed current state of blissful Net Neutrality. A list of ISPs that limit
BitTorrent bandwidth is in this week's links, though most of them are, so far,
outside the United States.

BitTorrent blocking or limiting can be defeated by encrypting the torrents, but
that increases overhead, causes a bigger bandwidth hit, and defeats local
caching schemes that might help reduce bandwidth demand. So blocking BitTorrent
actually makes life worse for all of us, which may be why most U.S. ISPs aren't
doing it.

So let's assume that ISPs are allowed to offer tiered services. What impact will
that have on BitTorrent? The answer lies in the nature of the TCP/IP protocol.
Here is an analysis from a friend who is far more savvy about these things than
I am:

"If you look at the amount of overhead TCP needs it's exponential to how slow
each connection is; the slower (the connection) the more overhead because the
window sizes are smaller and more control packets are being used for
verification. And you know what? BitTorrent is FAR WORSE. 
Remember that for each file you download on BitTorrent you connect to dozens,
possibly even hundreds of people, and the slower each of those connections is
the more the overhead increases.

"About a month ago the amount of torrents I may (have been) automatically
downloading at any given time was between 10 and 30. This means that I was
getting no more than 1Kbps from every peer, which meant about half of my
bandwidth usage was in BitTorrent protocol overhead and not in downloading file
data. I brought this (overhead) down (by 40
percent) by just having five torrent downloads at a time and queuing the rest,
and I even got the files faster. I then did some more scheduling and what not to
get (my bandwidth use down by a total of 70 percent) and I still downloaded
about the same amount of real file data.

"So what happens when everyone's VoIP or other preferred packets get preference
over my torrent packets? Since I have no knowledge of the other people's usage
in my aggregate network I can't adjust well for changes in the network. The
BitTorrent traffic that is going will have exponentially increased overhead due
to the slow downs, increasing overall Internet packet overhead (with BitTorrent
already 30+ percent of all Internet traffic). Which means that allowing the
telco's to subsidize the cost of improving their infrastructure by having
preferred packets could exponentially increase the cost accrued by the larger
internet and backbone providers just to keep costs down at the aggregate level."

To recap: Giving priority to some traffic puts a hurt on other types of traffic
and when that other traffic constitutes more than 30 percent of the Internet,
the results can be severe for all of us. On the Internet everything is
connected, and you can't easily ignore the impact of one service on another.

With this new knowledge I did a simple test that you can do, too. I have a
Vicomsoft Internet Gateway that does very fine traffic shaping, though there are
many similar products available, like ClarkConnect and some others that are open
source. Many routers can do traffic shaping, too. I did a couple BitTorrent
downloads of specific files, measuring how much time and total bandwidth was
required. Then I deleted those files, changed my Internet Gateway settings to
give priority to my Vonage VoIP packets, called my Mom on the phone and started
downloading the same two BitTorrent files.

Vonage and many other VoIP services use an Analog Telephone Adapter
(ATA) device to connect your phone to the network. That ATA can do traffic
shaping, too, which requires that it be connected inline between your broadband
modem and router. Of course I didn't realize this until AFTER my test was done.

My test results were clear. I had no problem downloading the same BitTorrent
files, but it took longer. That was no surprise. After all, I WAS talking to my
Mom, which would have taken some bandwidth away from BitTorrent. But the more
interesting result was that the total bandwidth required to download the same
files using traffic shaping versus not using traffic shaping was almost 20
percent more, which undoubtedly came down to increased BitTorrent overhead due
to contention and retransmissions involving the priority VoIP service.

Traffic shaping causes different patterns on the local network, especially
aggregate networks that use creative technologies to send Ethernet frames over
old telephone and cable infrastructure. It's taken a very long time to get
Internet technologies to where they are today, and all the protocols built on
top of those technologies operate under certain assumptions. Just like a web
site sent over TCP assumes that TCP will make sure all the packets will get to
their destination, rich application protocols like BitTorrent operate under
assumptions like known patterns in bandwidth changes on aggregate networks.

Let's say Net Neutrality goes away and the broadband ISPs start offering tiered
services. My simple test suggests that one possible impact is that Bit Torrent
traffic, which currently uses, say, 30 percent of Internet bandwidth, is going
to expand to about 36 percent simply because of inefficiencies created by the
tiered services. This will increase the backbone costs for ISPs and will take
back at least some of the very performance advantage they are supposedly selling
to their priority customers.

The result of ending Net Neutrality under this scenario, then, is that the ISPs
make money from tiered services but with higher overhead costs and lower
priority service levels than one might expect. The ISPs then might try banning
BitTorrent to keep it from messing with their tiered services, but we've already
establish this can't practically be done on a technical level because torrent
encryption can always get around the ban. The only way, in fact, to limit
BitTorrent traffic would be to have it made illegal and now we're back again to
the clueless Congress that started this whole mess.

I don't think these latter ideas are even in the heads of broadband ISPs. They
simply haven't thought that far. But eventually, as they try trimming this and
expanding that to solve a problem that shouldn't have existed in the first place
and can't otherwise be solved, they'll come up with something all of us will
hate. I guarantee it.

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