Network end users to pull down 2 gigabytes a day, continuously?

Michael.Dillon at Michael.Dillon at
Mon Jan 8 10:25:54 UTC 2007

> But what happens when 5% of the paying subscribers use 95% of the 
> capacity, and then the other 95% of the subscribers complain about poor 
> performance?

"Capacity" is too vague of a word here. If we assume that the P2P 
software can be made to recognize the ISP's architecture and prefer
peers that are topologically nearby, then the issue focuses on the 
ISP's own internal capacity. It should not have a major impact on
the ISP's upstream capacity which involves stuff that is rented 
from others (transit, peering). Also, because P2P traffic has its
sources evenly distributed, it makes a case for cheap local
BGP peering connections, again, to offload traffic from more
expensive upstream transit/peering.

>  What is the real cost to the ISP needing to upgrade the
> network to handle the additional traffic being generated by 5% of the
> subscribers when there isn't "spare" capacity?

In the case of DSL/Cable providers, I suspect it is mostly in
the Ethernet switches that tie the subscriber lines into the

> The reason why many universities buy rate-shaping devices is dorm users 
> don't restrain their application usage to only off-peak hours, which may 

> or may not be related to sleeping hours.  If peer-to-peer applications 
> restrained their network usage during periods of peak network usage so 
> it didn't result in complaints from other users, it would probably 
> have a better reputation.

I am suggesting that ISP folks should be cooperating with
P2P software developers. Typically, the developers have a very
vague understanding of how the network is structured and are
essentially trying to reverse engineer network capabilities. 
It should not be too difficult to develop P2P clients that
receive topology hints from their local ISPs. If this results
in faster or more reliable/predictable downloads, then users
will choose to use such a client. 

> The Internet is good for narrowcasting, but its
> still working on mass audience events.

Then, perhaps we should not even try to use the Internet
for mass audience events. Is there something wrong with
the current broadcast model? Did TV replace radio? Did
radio replace newspapers?

--Michael Dillon

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