Re: [p2prg] New version of p2prg-mythbustering

[Ray.Bellis at nominet.org.uk]

Have you considered the case where the ISP might prefer that
their users *not* localise the traffic? 

The dominant wholesale xDSL technology in the UK is BT's IPStream product.
All customer traffic is backhauled via L2TP to the ISP's network (almost
always to London telehouses) and no geographic localisation is possible.

This means that two neighbouring customers of the same ISP are no closer
in network terms than two customers at opposite ends of the country. 

Why this is particularly significant for UK ISPs is that BT's IPStream
backhaul product ("BT Central") is typically 10 times more expensive
than global IP transit. Currently BT charge at least £100 per Mbps pcm,
whereas volume IP transit can be had for £10 per Mbps or even less. 

If two customers mutually exchange traffic at 1 Mbps continuously
it'll cost the ISP £200 per month.  If one of the parties is off-net
it'll only cost them £110.

Hence IMHO for most UK ISPs it's better for their leeching customers to
be getting their data from a neighbour that's *not* on the same
network. 

Ray 

-- 
Ray Bellis, MA(Oxon) MIET
Senior Researcher in Advanced Projects, Nominet
e: ray at nominet.org.uk, t: +44 1865 332211