Internet Structure
Contents
Given millions of access ISPs, it is not feasible to connect all of them to each other, as it is not scalable.
In fact, it would take O(n^2) connections.
- Access ISPs connnect to Global ISPs.
- Access ISPs may instead be connected to Regional ISPs, which are connected to Global ISPs.
- Global ISPs interconnect via Internet Exchange Points (IXPs), and can also peer directly.
- Content providers / CDNs may run their own ISP network.