Temu se drugace rece CDN (Content delivery network) - lahko poisces :)
Vem da je ponudnikov vec, vsa velika omrezja to podpirajo, recimo Amazonov S3 ... drugace pa je vedno vec tudi manjsih ponudnikov npr. aiCache.com, enomalism.com, ...
Se teoreticna podlaga, kako to dosezejo - seveda preko DNSa, ampak je kar malce zastrikano :P
A very different, albeit less granular, way to accomplish the same is to use Internet routing (BGP protocol) to advertise routes to the same IP addresses from multiple points of presence. For example, let's imagine one has 4 DNS clusters, each cluster containing 4 nodes with IPs of 1.1.1.1, .2,.3 and .4.
Each cluster is positioned at a major peering point : US East Coast, West Coast, one in EU and one in Asia. From each location, one advertizes, via BGP, the same subnet with our DNS servers on it. Mission accomplished ! Through magic of routing, users in Asia will have their DNS requests come to one's DNS servers in Asia, EU to EU and so on. It is easy to see how this implied knowledge of requestor's geo location can now be used to direct their traffic in a certain, location-specific way. We use a lower value of DNS TTL setting, so that we can assure any DNS changes take place within reasonably short amount of time.