How to get multiple DNS Geo balancing entry points

I am facing a problem. I will set up a CDN with multiple dedicated servers in multiple zones (Asia, US, Eu), and I will set up an entry point with Nginx proxy with geoip routing.

But with this solution I just move the problem higher. Because this load balancer needs to be somewhere in the world ... if I set it in US, the Asia traffic will be very poor and vice versa...

I see solution like GeoDNS by clouddns but I don't understand how it is working ...

Has someone already solved this issue ? :)

Thanks

Some DNS hosting providers (and when you host your own dns some products allow you to do the same) allow you to set up geodns where, depending on the source IP-address of a dns requests, you can tailor the response.

For example when users request www.example.com you can return the CNAME www-us.example.com for US users and CNAME www-ap.example.com for users from Asia Pacific. For most users that will result that although they all use www.example.com in their browser URL bar, they will be directed to specific servers that are then geographically nearby.

Like any IP to geographic location scheme that won’t be completely fool proof and accurate, but it should work as intended for a large part of your user base.