Restricting requests to carrier specific IP address ranges is one way to detect carriers. It is the only method to guarantee a request comes from a specific carrier. As such, it is often used in sites that have billing. The down side to this method is it makes it impossible to test the site from a PC browser (unless the IP of the testing computer is added to the ranges for a given carrier).
Carrier |
IP Address Ranges |
docomo |
http://www.nttdocomo.co.jp/english/service/imode/make/content/ip/index.html |
KDDI |
|
EMOBILE |
|
WILLCOM |
http://www.willcom-inc.com/ja/service/contents_service/club_air_edge/for_phone/ip/index.html |
