The Stack Archive

IXPs fundamental in achieving safe and reliable net-neutrality

Tue 17 Nov 2015

Crossing roads

harald-summaGerman internet pioneer and entrepreneur Harald A. Summa, CEO at carrier and data centre-neutral internet exchange point (IXP) DE-CIX, discusses the development of the technology and explains its regional differences…

The importance of IXPs in networking

The internet is not a single network as such, but consists of nearly 55,000 autonomous networks. An internet exchange point (IXP) is the place where several networks can connect to each other in a simple straightforward way, in order to interconnect these entities. In the early days of the internet, one IXP per country was more than enough to bring all national internet service providers (ISPs) together. Some IXPs then went on to become of international importance, creating ‘gravity’. The more networks that interconnect at a single spot, the more data centers are needed, and the more attractive this particular spot becomes.

IXPs and data centers are eco-systems that rely on each other. Content providers want to bring their traffic as close to the end user as possible. Therefore, they bring it close to an IXP, or allow it to be brought to an IXP via a CDN. The idea is to keep local traffic local and use the IX as a distribution platform. Today, most of the traffic we see is video-based, user-generated, or produced as a stream of some kind. This leads to ever-growing traffic volumes that have to be cleared. By now, we have content providers and CDNs that are connected to an IXP with 1 terabit or more capacity. Three out of the five largest switches in the world, are at DE-CIX – they are capable of more than 100 terabit/sec traffic.

The more ISPs, and content delivery networks (CDNs) that are interconnected at an IXP, the fewer additional connections an ISP needs somewhere else. The best case for an ISP is one IXP connection and one transit connection, and you are ready for business! IXPs also make the network safer and more reliable, and are crucial for achieving net neutrality.

Innovation and development of IXP technology

In the old telecommunications world, data centers were run by the government. Carrier-neutral data centers were actually developed in the early nineties in line with the liberalization of the telecommunication markets. Places were sought where you had the possibility to come in with the carrier of your choice. These places offer competition and prosperity. We still have countries where this sort of data center is unknown, but they are becoming islands in the sea of nowhere.

IXPs are not regulated anywhere in the western hemisphere. However, there are some countries that work towards International Telecommunication Union (ITU) standards and are still dominated by governments. These countries often feel that they are missing out on something – and that is the gravity that carrier-neutral data centers and IXPs are generating.

The next phase of IXP development will look at virtualization, software defined networks, and direct cloud connections. Companies will also start to peer directly with each other or to the cloud via IXPs.  A lot of innovation is also taking place, paired with new business models and new hardware and software developments.

Regional IXP models

There are big differences between the European and the U.S. models of IXPs, and Asia is even more divergent. The U.S. data center and IXP market developed commercially much faster than, and very differently from, the European market. IXPs became an additional, carrier-neutral service from the data center provider. Via the process of concentration that the U.S. data center market went through, the gravity of IXPs diminished and IXPs lost their importance. As a result, ISPs moved over to private interconnects as a rule.

North American IXP models are commercially driven and part of a data center, and generally oriented towards private interconnects. Looking at the Asian model, IXPs are owned by large corporations like Yahoo or Softbank, whereas in the European Union, IXPs are generally community-driven and financed, non-profit and neutral.


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