[e2e] Re: crippled Internet

David P. Reed dpreed at reed.com
Thu Apr 19 21:50:21 PDT 2001

At 11:04 AM 4/18/01 -0400, RJ Atkinson wrote:
>         It is well known that the technical limitations of
>cable modem networks include the asymmetric bandwidth
>(very limited upstream capacity, relative to downstream)
>and the shared nature of the bandwidth (more like big yellow
>Ethernet than the modern switched stuff).

Not well known (or obvious) at all.  HFC systems are not your grandfather's 
cable modem.  You can partition downstream and upstream balance across a 
wide range, especially if you use DWDM on the upstream segments, and even 
more so since one can run fiber bundles for about the same cost as a single 
fiber, so the upstream ends can be much fatter than local 
distribution.  FTTH (which is where HFC evolves eventually) is even more 

Why does a cable distribution system have to remain hierarchical?  Already 
lots of systems have cross links for redundancy in case the upstream cables 
are cut.

- David
WWW Page: http://www.reed.com/dpr.html

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