Internet Exchange Point
An Internet Exchange Point is a central hub where many network operators interconnect their lines and exchange data directly with one another. This makes connections faster and cheaper than if every data stream had to take long detours through foreign networks.
The internet does not consist of a single network, but of tens of thousands of separate networks. These include phone providers, cable providers, universities, large companies, and video portals. For an email to get from one network to another, these networks must be physically connected somewhere. That is exactly what happens at an Internet Exchange Point: it is a building full of technology where many network operators plug their lines into shared distribution equipment. Each operator only pays for the connection and can then exchange data with everyone else present. You can think of it like a freight rail yard where many railway companies hand over their wagons directly to one another instead of rerouting them across the country.
Short paths, low costs
Without such hubs, every network would have to hand off its data to a large transit provider. Transit means that another network carries the data onward for a fee, often over hundreds of kilometers. This costs money per unit of data transferred. At an Internet Exchange Point, however, two networks usually exchange their data for free, because both sides benefit from it. This mutual agreement is called peering.
The second advantage is time. Data travels as light signals through fiber optics, and every detour lengthens the delay. If a German user streams a video from a German provider, the signal should not have to travel via London or Amsterdam. A nearby node often pushes the delay down from over 100 milliseconds to under 10. In online gaming and video calls, this difference is clearly noticeable.
For entire countries, this is an economic issue. Regions without their own exchange node pay a lot of money for having their data traffic processed abroad. That is why development banks and regulatory authorities promote the establishment of local nodes. This also has political relevance, because data traffic that stays within the country is subject to fewer foreign laws.
What’s really inside the data centers
Technically, an Internet Exchange Point is first and foremost a very large network switch, so to speak. Each participating network operator runs a fiber optic cable there and receives a port, i.e., a connection. Common sizes today are 10, 100, or 400 gigabits per second. All participants thus hang on a shared network, similar to computers on a school network.
The operator of the node does not forward the data itself, nor does it read it. It merely provides the socket and keeps it running. Who exchanges data with whom is negotiated between the networks themselves. This coordination runs via a protocol called BGP, through which networks tell each other which address ranges they can reach. If two networks fail to reach an agreement, they simply ignore each other, even though they are connected to the same switch.
For security reasons, such a node is usually spread across several data centers in a city. If one location fails due to a power outage or fire, the others take over. A common misconception is that the internet has a central hub that could be switched off. Large nodes are important, but in the event of an outage, data finds its way to its destination via other routes — just slower and more expensive.
DE-CIX, Frankfurt, and the numbers in the news
The best-known node in Germany is DE-CIX in Frankfurt am Main, one of the largest in the world. At peak times, several terabits per second flow through it — that is, several trillion bits every second. Such record figures regularly appear in the news, for instance during major football matches or new game releases. Other large nodes include AMS-IX in Amsterdam and LINX in London.
In everyday life, you notice nothing of these places, yet you benefit from them constantly. Whether a video starts without buffering or a video conference runs smoothly often depends on how well your own provider is connected to such nodes. Disputes over peering agreements are a recurring topic when providers disagree about the costs of video traffic. For investors, data center operators and network operators are therefore closely tied to this infrastructure. The AI boom is reinforcing this as well, since data centers need to move enormous amounts of data between locations.