Matti Aarnio wrote:
>
> On Tue, Oct 05, 1999 at 10:06:37AM -0400, Geof Goodrum wrote:
> ...
> > In Alexandria Virginia USA, both the up and downlink rates are currently
> > 3Mbps (it's a fiber network). However, @Home is putting in uplink limits
> > (128Kbps, I believe) in their service areas to reserve bandwidth for
> > shared network residential use. They do not permit Internet server
> > applications...
>
> No wonder. Cable-data environment is very much assymmetric
> system. Channel capacity is shared, 30 MB (or so) towards
> users, and uplink (shared, too) is mere 0.7 kB (or 1/40th)
> of the downlink..
>
> If people are just pulling in data (like web-pages), their
> uplink traffic is mostly TCP ACKs (40 byte IP packets + MAC-
> frame) outwards, but large frames towards themselves. Optimum
> performance is likely achievable for data frames of size
> 40 * (40+30 bytes) = 2800 bytes
> which, by the way, is way more than your average 1500 byte
> MTU at server Ethernets...
>
> So, even to get maximum performance out of the downlink
> capacity, you would need more uplink capacity, or TCP-SACK
> feature. (Getting 1/10:th of maximum downlink capacity is
> no big deal, IMO. It just tells that there are other limits
> before cable downlink. No HTTP proxies at the cable head-end ?)
>
> > ... (the big reason I didn't join up, I was planning to run a web
> > server). My parents use it with Win95, and I've found the actual
> > downloads do approach 3 Mbps. Very nice.
>
> If I were at cable-data industry, I would not allow running
> own servers either - however I would (very likely) have
> a web-hotel available for those pages for some moderate
> fee (or included in the service base price).
>
> > Geof Goodrum
>
> /Matti Aarnio <[EMAIL PROTECTED]>
> -
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> the body of a message to [EMAIL PROTECTED]
If I can't run services why would I want to sign up. DSL is available
in
most areas where cable modems are, they offer dedicated line that is
just
as fast and is not shared and at near the same cost.
At least here cable- $95.00 install $45.00/mo dsl- $100.00 install
$50.00/mo
and no restrictions on what I do with my bandwidth.
--
Jeff Largent ImageLinks, Inc.
System Admin Melbourne, Fl 32935
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