🚀 go-pugleaf

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

That's my understanding as well -- see my analysis in
<news:%oXe6.200$Tf1.8852@typhoon.sonic.net>.


In <3A7C18EA.E57AAF66@mynetwatchman.com>, Lawrence Baldwin
<baldwinlSPAMMENOT@mynetwatchman.com> wrote:

>I didn't think the amount of upstream bandwidth was even THAT high,
>Randy.
>
>Ingress noise just KILLS upstream bandwidth...this doesn't happen on the
>fiber part
>of HFC, but you still have quite a bit of coax.  I thought it was much <
>10Mbps potential, and
>reduced even further due to noise issues.

>"Randy S." wrote:

>> Well, let's see, I believe a cable segment supports 54 Mbps download and 20 Mbps upload
>> typically (I believe that they can vary this by how many channels they dedicate to
>> delivery, I think there is 27 Mpbs down and 10 Mbps up per channel) .  If a segment has say
>> 270 users on it (assuming a 100:1 oversubscription ratio that John used as typical for DSL
>> earlier), each capped at 2 Mbps download, 384 Kbps upload (I think that's typical?) it
>> would take 20,000 / 384 =  52 users uploading at maximum rate to saturate the upstream
>> stream.  Of course since many other people are ALSO uploading at normal rates, the real
>> number would be somewhat lower.  Realistically, I would say 25-35 people uploading
>> aggressively would effectively "kill" the segment.  Does that sound right, John?  The
>> kicker here is that this would happen even if they were all just uploading files to others
>> on the same segment!

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