Site to Site Peering
Peering is a method that allows two networks to connect and exchange traffic directly without having to pay a third party to carry traffic across the Internet.
The Internet consists of over 25,000 autonomous systems that independently route traffic. Peering is often used as a method by which these systems can interact and exchange traffic, allowing it to flow from one end user, over the Internet, to another end user.
This method is a necessity for interconnected companies, Internet service providers (ISPs), content delivery networks (CDNs), and backbone service providers.