I need to know about the technology and how the solution/company (such as Akamai) caters its customers. Do they mirror the content across their server's network? If this is the case then how a request is directed to the closest and lightly loaded server on Internet? There are other hardware (GSLB on F5, BigIP and Cisco CSS) and software (ultraDNS) solutions in the market as well but its difficult to relate those with a CDN solution such as of Akamai's or others. Does anybody have experience with F5 or BigIP GSLB solutions? I would appreciate if somebody can help me out here as well.

The answer to such general questions is called "know-how". Companies in business of selling products based on the "know-how" tend not to tell their competitors how that "know-how" works, since those companies spent millions of dollars developing that "know-how" from the paying the pointy-headed Ph.D.s to do theoretical work to spending enormous amounts of money on deployment. The way to benefit from the "know-how" without spending all your money on the pointy headed Ph.D.s is to buy/license/use it or hire a team or people who in exchange for something else (such as money, sex, suitcases of cocaine, F-18s) will either provide that "know-how", develop a "know-how" or explain to whoever hires them that it is cheaper to buy the service. As far as F5 or BigIP go, they work just fine for website load-balancing. Alex