Comcast blocking p2p uploads

Sun Oct 21 00:46:34 UTC 2007

Leo Bicknell wrote:
> I'm a bit confused by your statement. Are you saying it's more
> cost effective for ISP's to carry downloads thousands of miles
> across the US before giving them to the end user than it is to allow
> a local end user to "upload" them to other local end users?
>   
Not to speak on Joe's behalf, but whether the content comes from 
elsewhere on the Internet or within the ISP's own network the issue is 
the same: limitations on the transmission medium between the cable modem 
and the CMTS/head-end.  The issue that cable companies are having with 
P2P is that compared to doing a HTTP or FTP fetch of the same content 
you will use more network resources, particularly in the upstream 
direction where contention is a much bigger issue.  On DOCSIS 1.x 
systems like Comcast's plant, there's a limitation of ~10mbps of 
capacity per upstream channel.  You get enough 384 - 768k connected 
users all running P2P apps and you're going to start having problems in 
a big hurry.  It's to remove some of the strain on the upstream channels 
that Comcast has started to deploy Sandvine to start closing *outbound* 
connections from P2P apps.

-Eric