North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: The Great Exchange

  • From: Jim Dixon
  • Date: Wed May 27 17:05:33 1998

On Wed, 27 May 1998, Perry E. Metzger wrote:

> "Pickett, David" writes:
> > 1) More needs to be done to leverage locality of traffic
> In the long run, why are we assuming there will be locality of
> traffic?

I don't know how carefully this topic has been studied, but in
the UK, where it is easy to distinguish local traffic from non-UK
traffic, there most certainly is locality of traffic.

It's easy to distinguish local traffic because nearly all UK 
traffic flows to the LINX, still the UK's major peering point;
other traffic goes to international circuits.  Most larger ISPs
will have one or two LINX connections and one or more 
international links.  It's a no-brainer to count the packets going
to each.  These counts ignore packets staying within a given 

As far as I know, for all larger UK ISPs (those with good peering),
most traffic stays in the UK.

> It is true that the old PSTN has locality of traffic, but it doesn't
> have flat rate pricing, or the usage patterns that the Internet has. I 
> argue that users are rarely more likely to be trying to download a web 
> page from near to their homes than from far away.

Terms like "near" and "far away" are uncomfortably vague in this 
context.  However, I am sure that UK users are most likely to hit
UK Web pages first, then US Web pages, with (say) French Web pages
far behind either.  And Calais is 20 miles away, whereas the USA is
3500 or so.
>                                                  If there is
> locality, it is probably weak, and in the long run would only account
> for a fraction of the traffic.

Our experience isn't like this.  The effects of locality are obvious,
but locality is not always just a function of georgraphy.

Jim Dixon                  VBCnet GB Ltd 
tel +44 117 929 1316                             fax +44 117 927 2015