One goal in building the efficiency and performance needed to send content resources to end users is to flatten existing Internet architectures. Whenever possible, you eliminate Tier 1 Internet networks from participating in sending content resources to end users.
How do we complete this task? One option is to develop and use commercial Internet Exchange Points (IXP), locations where many content networks and resources allow the Internet to meet to connect with each other as partners.
According to Wikipedia, IXP is a physical infrastructure that allows different Internet Service Providers to exchange Internet traffic between their networks (autonomous systems) through mutual peering agreements, which allow traffic to be exchanged at no cost. IXP is basically a physical switch in a hotel operator or data center with the capacity to connect thousands of networks simultaneously, both content providers and network providers.
Today on Any2 Exchange, IXP is built inside One Wilshire, on one switch 125 different networks are interconnected and can freely pass traffic to each other without having to go to Tier 1 for routing. Members pay a small annual fee to Any2 Exchange for a one-time connection and then benefit from a "peeping" relationship among members of the Internet exchange.
Akamai, for example, a large content distribution network company that sends streaming media and movies on demand, can connect to American Internet Services, ISP Tier 3 in San Diego, California, through local or regional Internet exchange points such as Any2 Exchange, Palo Alto Internet Exchange ( PAIX), or other large exchange points operated by data centers and hotel operators.
When American Internet Service users want to watch movies available on Akamai's content delivery network, the data is passed directly from Akamai to American Internet Services - and subsequently to end users - without transit of any other network. Not only has the goal of being less Tier 1 dependent, but the performance is superior because there is no "leap" between CSP and ISP. Whenever you can cut the transit network, you improve the end user experience. Plus, this is more economical, because in the case of CDN moist and ISPs do not have financial solutions to exchange data.
https://www.internetan.gratis/apa-itu-internet/