On Jun 13, 2005, at 2:55 PM, william(at)elan.net wrote:
Commercial service when there are several free ones available....
BTW - based on what I can see they are not updating data once per day but only once/month. Also having some experience in this matter I highly doubt that its much more accurate then what I got - it appears no matter what path you take to get the data, it would to a degree be wrong (difference being which part is wrong). One possible way to resolve some issues could be to have testing servers placed in several locations and analyze TTL for connections to various ips to determine how far its from several servers - of course it would also not be accurate as ip networks are not necessarily interconnecting in the same region (CAIDA did their best with this method some time ago but have not kept updated data as far as I know).
Too bad no one has servers in 100s or even a 1000 or more ISPs in dozens of countries with TCP connections to a statistically significant portion of the Internet on a daily basis who could possibly measure, say, RTT (not sure why TTL is relevant) and other things, and perhaps use that along with other information to create a database that they could then give to customers who need geo-location data for their "mission critical" applications. That would probably be pretty darned accurate. Of course, that would be a "commercial service".... =) -- TTFN, patrick