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

Brandon Butterworth brandon at
Sun Jan 7 15:17:14 UTC 2007

> Increased bandwidth consumption does 
> not necessarily cost money on most ISP infrastructure. 
> At my home I have a fairly typical ISP service using 
> BT's DSL. If I use a P2P network to download files from
> other BT DSL users, then it doesn't cost me a penny
> more than the basic DSL service. It also doesn't cost
> BT any more

It does cost BT, as I said someone pays even if it's not obvious
to the user

> The only time that costs increase is when I download
> data from outside of BT's network because the increased
> traffic reaquires larger circuits or more circuits, etc.

Incorrect, DSLAM backhaul costs regardless of where the traffic
comes from. ISPs pay for that, it costs more than transit

> The real problem with P2P networks is that they don't 
> generally make download decisions based on network
> architecture.

Indeed, that's what I said. Until then ISPs can only fix it with P2P
aware caches, if the protocols did it then they wouldn't need the
caches though P2P efficiency may go down

It'll be interesting to see how Akamai & co. counter this trend. At the
moment they can say it's better to use a local Akamai cluster than have
P2P taking content from anywhere on the planet. Once it's mostly local
traffic then it's pretty much equivalent to Akamai. It's still moving
routing/TE up the stack though so will affect the ISPs network ops.

> I have to admit that I have no idea how BT charges
> ISPs for wholesale ADSL.

Hence your first assertion is unfounded

> If there is indeed some kind
> of metered charging then Internet video will be a big
> problem for the business model. 

It is, BT Wholesale don't give it away (usage or capacity
based ISPs still have to pay)

> The difference with P2P is that caching is built-in to
> the model, therefore 100% of users participate in 
> caching.

But those caches are in the wrong place, they'd be better
at the ISP end of the ADSL

> With HTTP, caches are far from universal, 
> especially to non-business users.

Doesn't matter if they're buying P2P caches they could buy HTTP if they
don't have one already. The point is they're buying something


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