Cable/DSL "shared" access myth (was Re: [TriLUG] Port 25 blocked)

[Jeremy Portzer]

On Tue, 2004-05-18 at 15:32, Stephen Hoffman wrote:
>    I'm still feeling the service out, but so far I love it...The reason I
> stayed with DSL was the dedicated bandwidth (I'll sacrifice speed for
> consistancy). 

The idea that DSL has "dedicated" bandwidth is one of the biggest myths
of broadband Internet.  Sure, the bandwidth is "dedicated" from the CO
(Central Office) or DSLAM (DSL access module) for the "last mile" to
your home or business.  But it's not dedicated from there upstream! 
You're still sharing bandwidth with your neighbors, and anyone else at
at your ISP, where the ISP connects to the Internet backbone!  Plus,
your DSL modem has significant bandwidth caps that negate how much of
the backbone you can use anyway.

A cable modem connection shares the cable with your immediate neighbors;
usually a very small number like 10-15 (maybe slightly more in
apartments).  But this doesn't matter, because the capacity of the cable
modems is high (55 Mbit or something).  Your individual modem is limited
to a much smaller value (with TWC it's usually 3 Mbit down/384Kbit up). 
So you're never going to be in contention with your neighbors anyway!

The fact is, cable modems offer much more bandwidth for the money
(standard DSL in this area is often 1.5 down/128kbit up -- Cable is
twice the download and three times the upload speed).  Cable is usually
slightly less absolute cost than DSL ($41.95/mo. for Earthlink vs. 49.95
for full DSL service).  Sure, both cable and DSL can become congested
during peak periods when the Internet *backbone*  -- the ISP's upstream
connection -- becomes clogged.  But you should NEVER have any problem
due to congestion in the "last mile" section, even though this is
technically "shared" in cable access.  The shared access segment is
simply not a factor in your connection's speed or utility!

>  I'm not quite sure if this is a by product of the
> upgrade, but it seems that when I ssh home (and only ssh) that my
> keystrokes are heavily delayed?  but I might just need to restart ssh
> (been up for over 100 days?)

No, the ssh daemon's uptime has no relation to anything.  If your
keystrokes are being delayed (known as high latency), that could mean
that you are downloading or uploading something in the background that
you aren't aware of (check for trojans, rootkits, etc).  It may also be
a misconfiguration with the telco or ISP's equipment.

>    As far as the process all I really did was go online and change my
> service...two days later I lost internet in the middle of the night...I
> restart and I now have a free static IP and consistantly download at
> 300K and upload at about 45K so the speed is about on par with what I'd
> expect.  Losing mail wasn't the biggest pain in the ass, although I'm
> sure the list got more then it's fair share of bounces from me
> (sorry!).
>    So so far, I'd say go for it...I didn't have to re-commit for any time,
> no cost to upgrade and I'm only paying $47 and change after taxes, up
> from $45.  For twice the speed and a static IP, I'll gladly pay $2.00
> 

This does sound like a good deal, and I don't have a problem with your
choosing it based on speed, static IP, etc.  But please don't believe
that somehow your "dedicated" connection is any better because of that.

--Jeremy

-- 
/---------------------------------------------------------------------\
| Jeremy Portzer        jeremyp at pobox.com      trilug.org/~jeremy     |
| GPG Fingerprint: 712D 77C7 AB2D 2130 989F  E135 6F9F F7BC CC1A 7B92 |
\---------------------------------------------------------------------/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
URL: <http://www.trilug.org/pipermail/trilug/attachments/20040518/a6e2fce8/attachment.pgp>