...
- They are really in the country and not a proxy elsewhere (we use GeoIPTools to identify the country).
- GeoIPTools has a city for the site.
- The host is a web server - this often enables us to find out more about the site via the web.
- The site is an educational or government site (in that order of preference).
- Sites within a country are chosen for diversification, i.e. different cities, different uses (Education, Government, Commercial...), different IP network addresses.
- We choose sites that appear to have better connectivity (e.g.lower RTT).
- Where possible >= 2 sites/country (see Hosts per Country per Region).
Examples
- Republic of Congo: Illustrates the difficulty of finding www hosts in some countries.
- More examples can be found at http://www-iepm.slac.stanford.edu/pinger/hostsearcher.