Re: Comcast blocking p2p uploads

[Sean Figgins <sean () labrats us>]

Frank Bulk wrote:

> 2) DSL and fiber have limitations, too.  The modulation and spectrum width
> can vary, but most MSOs have their forward configured with a maximum of
> around 38 Mbps (256-QAM, 6 MHz wide) and the return in the 9 Mbps range
> (64-QAM, 3.2 MHz wide).  Charts here:
> Forward: http://www.cable360.net/images/articles/15131_1168455349.gif
> Return: http://www.cable360.net/images/articles/15131_1168455396.gif

Thank you, Frank.  I'm not a HFC engineer, but rather an 
IP/Network/Server/Security guy, that worked on the backbone and lab side 
of a large MSO.  My HFC experience is exclusive of what is between the 
CMTS and the cable modem.  I know just enough to be able to live there.

I got my figures reversed.  For some reason I was thinking that it was 
about 100 meg on the upstream and 45 meg on the downstream, but looks 
like I remembered it wrong.

Anyways, regardless of that, you pretty much validated what I was saying 
as to the reason why a MSO would deploy such a device.  It's possibly 
cheaper to do so than to deploy the hardware to split the HFC pland and 
increase available bandwidth to subscriber ratio.  Not that I agree with 
such a practice.

 -Sean