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 network. 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 http://www.vbc.net tel +44 117 929 1316 fax +44 117 927 2015