response 26 of 40:

Jun 7 01:40 UTC 2002

Cable is no less secure than DSL.

response 28 of 40:

Jun 7 07:57 UTC 2002

'Cable is no less secure than DSL' is an interesting statement.
'Cable' depending on your vendor and arch 'shares' a media - the
cable'  - which inherently means that a properly configured interface
can 'snoop' on all peer traffic and there is no way to prevent that.
(And given the usual pricing model of 'cable TV' the more 'hosts'
on the 'network' the better until the customers squeal like a butt-
fucked pig.)  DSL on the other hand at least means a fixed max
transfer rate to the point of congestions and means that
while I might share an upstream choke point I cannot easily 
monitor the traffic of my peers downstream.

response 30 of 40:

Jun 8 00:18 UTC 2002

Not really, if you're an end user.  You'd need the packets going by to be able
to turn on your sniffer and watch them.  The issue Windows seeing the boxes
running NetBEUI seeing the other computers as being in the same workgroup is
a bit different -- my understanding is that most of the DSL access
concentrators are set up to prevent this, but I don't know the details.

I know very little about cable modem technology, but my understanding is that
with many modern setups, the cable modem should only be bridging traffic
intended for its own user onto the customer's ethernet, so sniffing cable is
presumably more difficult than sniffing, say, an office LAN.  I assume some
sort of cable modem-like device would still be able to act as a sniffer,
though, unless they're also doing some sort of encryption.

response 32 of 40:

Jun 8 05:30 UTC 2002

If it's just broadcast packets, that would prevent anybody with a sniffer from
getting useful information.  The real danger would be if it were behaving like
a non-switched ethernet, in which case each end user would be able to see
everything, not just the broadcasts.

I think some older cable modems did work like that.  I don't know much about
it, though.

response 34 of 40:

Jun 14 06:56 UTC 2002

With cable modems, the wire you get in your house is electrically shared
with your neighbors.  Everything you send or receive is visible to them
and visa-versa.  I believe all modern cable modems perform filtering,
and won't let you see your neighbor's traffic (at least, not without
alterations).  At some point "upstream" of you and your neighbors, there
will be some form of repeater or amplifier.  This has to be "2-way" in
order for cable modems to work, but I believe this actually has logic
that separates out the data stream, such that people on different
branches aren't competing for each other's traffic (and also won't see
each other's packets.)

With DSL, the wire pairs you get in your house go all the way back to
the nearest switch.  The wire to your house isn't shared with anyone
else.  From the switch on outwards, your data does share bandwidth with
other people's data, but it would not be possible for you to spy on
other people's traffic (or visa-versa).  You might be able to see
cross-talk on your line, with special equipment, but it's more likely to
be voice than data.

The physical infrastructure with both cable & DSL is not well protected.
Typically, both travel via the same poles, over a combination of land
that is either public, attached to a public right of way, or over
private land that is generally not well secured.  DSL lines, like most
phone lines, probably go through several wire junction boxes that are
weakly, if at all secured.  Cable may be slightly more secure, but only
because any botch in tapping the line is likely to result in
interference that will attract attention from many people, and result in
a visit by the local cable guy to fix the wire.  Neither is protected by
gas lined cable runs, guard dogs, video surveillance, or live human
guards.

response 36 of 40:

Jun 20 01:23 UTC 2002

Well, we seem to have improved our DSL connectivity.  This weekend it
suddenly got a lot worse than it had been, so that instead of dropping out
a couple times a day, the DSL modem couldn't even connect most of the time,
and when it connected only lasted a few minutes.  Eventually I tried plugging
the DSL modem into the network interface box outside the house (picture man
sitting on lawn with modem and very long extension cord).  It connected on
every try.  So I decided there were problems with the wiring inside the house.
Not surprising - in most rooms we still have four-prong phone plugs.

Our DSL shares a line with our voice phones.  All the phones were plugged into
filters to prevent them from interfering with the DSL (or vice versa).  I
decided to rearrange things.  I split the phone line right were it came into
the house.  The DSL modem plugs into one branch.  The other branch goes
through one of the filters and then connects to the main terminal block for
all the old phone wiring in the house.  The idea being to isolate the DSL
from every other phone in the house.  Also I now need only the one filter
for all phones in the house instead of one on each phone.

We haven't had any connectivity problems since then.  It's only been two days,
so I'm still knocking on wood, but it looks good.

response 38 of 40:

Jun 20 17:07 UTC 2002

There are companies that will do it, but the only one I'm currently aware of
focuses on business customers.  The company I work for has an SDSL line that
doesn't provide a dialtone at a remote site.  The contract we had to sign
made sure we were aware that the line didn't provide any sort of phone
service, "including emergency service."

response 40 of 40:

Jun 20 18:08 UTC 2002

I called my ISP (don't ask why I didn't think of doing that earlier) 
and they confirmed, I need to keep phone service to have DSL service.  
Oh, well.