What are Internet Exchange Points?
According to Cloudflare, Internet exchange points, or IXP for short are “a physical location through which Internet infrastructure companies such as Internet Service Providers (ISPs) and CDNs connect with each other. These locations exist on the “edge” of different networks, and allow network providers to share transit outside their own network. By having a presence inside of an IXP location, companies are able to shorten their path to the transit coming from other participating networks, thereby reducing latency, improving round-trip time, and potentially reducing costs.”
How do they work?
IXPs essentially are physical locations that contain network switches routing traffic between different members networks. Networks share maintenance costs and otherr associated costs for various services, in a matter much the same as cargo shipping companies do here in meatspace. To minimize these costs, members will connect with one another to soften financial burdens and other drawbacks while cutting down latency.
The last 20 years have obviously shown a massive expansion in network interconnections and have brought upon the development of datacenters that host network equipment and large amounts of networks all due to the IXPs that now exist on the inside.
Why are IXPs important?
In short, they make the internet better, faster, and stronger. According to Stackscale, “ Using Internet Exchange Points has many advantages, but the most important ones are: cost reduction, latency and bandwidth improvements and an increase in routing efficiency and fault tolerance.”
BGP (Border Gateway Protocol)
Juniper networks says, “Traffic exchange between two members on an IXP is facilitated by the BGP routing configurations between them (peering session). Members choose to announce routes via the peering relationship – either routes to their own addresses, or routes to addresses of other networks…” In essence, BGP is the standardized global routing and reachability protocol of the entire internet that is used between autonomous systems. For more details on BGP, check out this article from Fortinet: What Is Border Gateway Protocol (BGP?
How do providers share traffic across different networks?
Providers share traffic through transit (paid service) and peering (free or settlement-free). Unfortunately, the data transference is usually only at a cost for the smaller networks while larger networks with equal share are more likely to peer with one another. When the relationship ends, it is known as depeering.