I watch this with amusement. Once I had no choice but DSL. It was from my
favorite, AT&T. It ranged from faster than dial-up by a very little to
slower to doesn't work at all, which was the biggest problem, as it would
take at least 3 hours of my time on the phone to India trying to get it
fixed. (my secret? After a few hours of pain, I would scream into the
phone, I WANT TO SPEAK TO SOMEONE WHO SPEAKS ENGLISH!!!! [Don't mean to
insult any members of the list that are of Indian descent, but few of you
who work in the telephone boiler rooms speak about half as much English as
you think} They would them return the call to a tech in Houston {Thanks,
Bill B} who would click around on his keyboard for about ten seconds, and
say, oh, yeah, that's what's wrong. Clickety click and it was fixed. For a
few days or a week. Then I got cable internet. Don't ask me how it works,
but it does. The drop from the pole to my house is copper, and it probably
is copper for a few blocks to their fiber. All I know is that it carries
Cable, phone and internet and all work great. If there is a problem, I call
their support, which is about a mile from my house (a selling point for
them), and things are back up in seconds. It ranges from fast to what they
used to call crazy fast, but don't anymore, perhaps in sensitivity to all
the crazy people who live here, quite a few.
Somewhere someone may get fast speeds with DSL, but not here! And not on my
in-law's farm, where their banjo playing phone company sold them DSL on a
contract that they are stuck with for several years, even though their DSL
is slower than the dial-up it replaced, and cant/won't be fixed.
From: Ken Norton [mailto:ken@xxxxxxxxxxx]
Sent: Wednesday, January 19, 2011 1:42 PM
To: Olympus Camera Discussion
Subject: Re: [OM] OT Internet connection speed
DSL is actually capable of some seriously high speeds, but is throttled at
the ingress (modem) to whatever it is that you are willing to pay for. By
effectively limiting the peak speeds, we end up with an easier to manage
network that prevents "Little Jan" down the street, who is file copying 2GB
of stolen audio/movie files to "Little Moose" across town during the evening
peak hours when Big Chuck has gotten home from work and is looking to just
check his 401K but can't because the network is crammed.
The cable-modem is essentially on a shared "ring" that is not unlike the old
token-ring networks of old. If you have one bandwidth hog, the whole ring
suffers. Entire neighborhoods are hooked up through as few as one ring. Each
ring decreases the number of TV channels that can be delivered.
DSL is a bit different because a DSLAM (Digital Subscriber Line Access
Multiplexer) is essentially functioning as an Ethernet Switch with each
subscriber arriving on its own physical port. In the cable-modem world, an
entire neighborhood arrives on just one port of a switch. As the port is
"shared" with your neighbors and there is rarely, if ever, any traffic
management or traffic shaping going on... (net neutrality is forcing many
carriers to remove traffic management and shaping which is causing further
degradation of service), the experience can be ruined by just one snot-nosed
brat, or somebody downloading a netflix movie.
However, that's just the "access" portion of the network. Once you get to
the switch/dslam, the backhaul from there to the BGP router can be
problematic. If you have, say, 6Mpbs of backhaul capability from a DSLAM or
switch, everybody served from that device has to share the same chunk of
space again. However, in the case of DSL, we throttle maximum speeds at the
ingress so no one subscriber is able to make too much of a dent on the
backhaul. Besides, depending on the technology in play (ATM or IP), there is
additional traffic shaping options available.
Statistically speaking, a DSL subscriber uses about 5% of his available
bandwidth. This means that we can statmux 20:1 on the backhaul links without
fear. However, that 5% is a 24/7 average, so you can experience peak load
issues. As you get farther and farther down the tree towards the BGP
router(s), you'll be somewhere around 200:1 or even greater with some
networks able to push over 2000:1 with traffic shaping and caching.
Nowadays, our standard is for 1GbE connectivity to the DSLAMs. The cost
differential between DS3 and 1GbE is minimal, so unless there are network
consraints, we just go for the optical connection and be done with it. We
don't actually need this bandwidth today, but it won't take long...
Oh, and my condo is between three fiber-optic runs--one of which is carrying
literally hundreds of OC-48, OC-192, 10GbE and 40GbE circuits. Iowa may be
flyover country, but you need Iowa to connect the places people actually
live.
AG
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