Figuring out what process is eating bandwidth?

[Ross Werner]

On Sat, 28 Jan 2006, Justin Findlay wrote:
> I agree.  In vain I've searched for a utility that will tell me
> network usage per process on the local machine rather than per network
> connection.  Inline on top would be perfect.  Perhaps that's the
> charge given unto us, Ross.  We need to write such a utility.

I'm up for the challenge ... but is it even possible to get such 
information? Ethereal and the like just listen on a network device for 
packets going in and out, but the network device itself doesn't have 
information about what processes sent those packets, does it? So that 
information would have to come from somewhere else. Netstat has 
information about what processes are connected to which ports, but it 
doesn't have any information about what packets are sent across those 
ports.

Would it be possible to tie the two together in user-space?

 	~ Ross