In order to get your browser to open your favourite website, after you enter the desired web address, your computer must start communicating with another computer somewhere else in the internet and obtain data required to display the page. Have you ever wondered how and where the data actually flow after leaving your computer?

In the early days, the Internet was not a worldwide computer network. It was rather an isolated cluster wired with transit connections. The biggest drawback was the fact that these transits were typically run by commercial operators who charged hefty fees for these services. Concepts such as redundancy (an option to get connection elsewhere in case of a blackout) or network independency (a condition where everyone has the same right to use the network), were not available much.

After overcoming these problems, so-called peering nodes appeared during the mid-nineties, which fundamentally changed the topology of the Internet and data flow paths. As the name suggests, a node is a point where individual networks connect. Peering nodes are usually neutral locations that allow connected networks (their operators, and content providers) to mutually interconnect and to exchange data between networks, and to allow data to flow directly without having to use an expensive transit connectivity.

In the Czech Republic, there are two major internet nodes: Public node NIX.CZ operated by an association of significant domestic operators and a commercial node Peering.cz. Our Slovak brothers for example, use the SIX node and a project called SITELiX. The largest node in Europe is AMS-IX in Amsterdam, German commercial node DEC-IX and LINX node in London. Each of these three nodes connects hundreds of leading global providers, therefore, do not try to picture the entire node in one place, in a single building. Most of the major hubs including, for example NIX.CZ is divided into several physical locations, and the greatest nodes have connection points even in different cities or countries.

Nothing is perfect

Thanks to peering nodes connected networks get better redundancy (they do not rely on one connectivity supplier), better capacity (data can be distributed across multiple networks), better control over data flows (where exactly data flow through the Internet), and last but not least, also a marketing triumph because the presence in prestigious peering nodes also improves the status of providers in the eyes of educated customers.

However, the interconnection of networks through peering nodes also retained one major disadvantage from the days of commercial transits. The disadvantage is a centralization, which means an opportunity for cyber pirates to run an extensive distributed attack on centres or on the connected networks. A huge amount of requirements on connected networks and servers will create a situation we have already witnessed in the Czech Republic in March 2013. A portion of the Internet is overloaded therefore, unavailable and not only to end users.

In order to prevent occurrence of these situations a new level of node connections – beyond the framework of traditional nodes, is being tested where selected providers complying with demanding criteria create a safe mutual peering, which in the case of a large-scale attack, will still provide availability of at least the selected networks. Under NIX.CZ, this project is called FENIX. Almost ten operators connected their networks under this project, including Seznam.cz, Cesnet, O2, Dial Telecom, Coolhousing and others.

A map of a portion of the Internet clearly shows individual nodes within the network. It reminds a neural network. “Image Source: Wikipedia, the free encyclopaedia”.

Global peering

It may seem that the ideal Internet solution would be a mass global peering, where the networks would be connected through as many nodes as possible. But we do not want to choke our planet with wires! However, we try our best to give major service providers the best connection possible. For example, Coolhousing the provider of hosting services and data center operator in Prague, joined the biggest European nodes AMS-IX and DE-CIX at the end of last year, which allowed Coolhousing to increase the data speed between its network and networks connected to those nodes by one third. We are talking in the order of milliseconds, of course, but in computer communication, milliseconds play an important role.

Simply put, peering nodes shorten Internet distances. They are the crossroads where data make turns from one street to another one. The closer your provider is to these largest intersections, the better for you. You will also be closer to your clients and servers connected to a network of other interconnected providers.

Author: Jirka Dvořák