🚀 go-pugleaf

[POSTED TO comp.dcom.modems.cable; PLEASE REPLY THERE]

In <3A7CB1BF.6610F3BB@home.com>, David Knight <david-knight@home.com>
wrote:

>I think it might be instructive to see customer speed experiences listed
>at :
>
>http://www.dslreports.com/archive
>
>Note the 3 fastest (downstream) providers listed are using Cable modem
>technology, not DSL.  Also, 10 of the top 14. This data is based on
>customer speed tests run across the country, and this is clearly not a
>cable modem web site.

At best, that kind of unverified anecdotal material is unreliable; at
worst, it can be highly misleading.  Regardless, it seems to me that
what matters are the typical (modal, median) speeds and the standard
deviations (variations).  Cable is indeed capable of very high speeds
under light loads, but by the same token it can be afflicted with very
low speeds under heavy loads, particularly if the shared uplink
saturates.  Published reports suggest that typical speeds in general are
roughly comparable for DSL and cable, with DSL seeming to have an edge
in typical speed and consistency.

>I think that both AT&T and AOL clearly have seen the benefits of Cable
>vs. DSL for broadband, and investigated how to engineer to its strengths
>prior to making their enormous investments.  ...

Perhaps, but AT&T is now struggling badly, and AOL probably had a lot of
objectives other than just access to cable.  Meanwhile, Excite@Home
stock has plummeted.  (Of course DSL providers are in the same boat --
consumer broadband is swimming in a sea of red ink.)

>I NEVER expect to see a
>scenario of even 50 customers CONCURRENTLY transmitting upstream on a
>HFC node/segment.

I would agree -- the architecture can't handle it.

>Modem deployments on HFC networks are well into 6
>digits, so scaling issues can and have been addressed. 
>
>As with all providers, there will be varying levels of transport service
>and no technology is immune to poorly designed network segmentation.

Agreed.

-- 
Best regards,
John Navas     <http://navasgrp.home.att.net/>
     CABLE MODEM/DSL GUIDE:  <http://Cable-DSL.home.att.net/>