[LINK] super-fast cable broadband (1)

[Richard Chirgwin]

Chris Maltby wrote:
> On Thu, Mar 12, 2009 at 02:01:55PM +0000, stephen at melbpc.org.au wrote:
>> Telstra today announced that its hybrid fibre coaxial cable broadband 
>> network in Melbourne will be upgraded to 100Mbps - more than triple the 
>> current peak speed - by Christmas. 
> 
> What the release doesn't say:
> 
> 1) The HFC network is a shared resource - the mythical 100Mbps is only
>    possible if no-one else on your cable segment is using anything and
>    then only under ideal conditions. If Telstra push ADSL users onto
>    their HFC network to keep their monopoly over the last mile, then
>    the bandwidth experience is likely to be much less than 100Mbps.
Chris,

While I agree that the 100M is hype, all Internet connections are shared
resources; the difference is where the sharing starts. If you're an ADSL
customer, sharing starts at the DSLAM; if HFC, on the customer segment;
on wireless, at the base station. We all get less than the theoretical
peak speed of the technology.

> 
> 2) The HFC uplink speed is a max 2Mbps upstream with DOCSIS3.0 - and
>    there may be a handful of upstream channels to share with the other
>    punters on your coax cable segment. I suppose there's a better
>    chance of getting VOIP and torrent type services going with a shared
>    piece of 2Mbps than with the 128Kbps of DOCSIS2.0 but it's still pretty
>    shabby when compared to ADSL, leaving aside Annex-M uplink speeds.
And that's the real issue. The disparity up/down is so much greater on
HFC as to inhibit what users can and can't do.

RC
> 
> You'd have to be an idiot to migrate from ADSL to HFC - say, a typical
> Telstra customer...
> 
> Chris
> 
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