home | About VIX | History
last change: August 04, 2019

History of the VIX

During the early years of the Internet, it was a common situation – particularly in Europe – to see packets with a source and destination address from within the same city to cross national boundaries twice, or even the Atlantic Ocean. Just because the customers happened to be connected to different ISPs (Internet Service Providers), the packets had to find the way to a common network node and then back again. Those network nodes, more often than not, were either located in a different country or even on the east coast of the USA. Eventually, in order to minimize such detours, Internet Exchange Points were set up to help groups of independent ISPs, serving customers in the same geographic area, to exchange packets locally.

The Vienna Internet eXchange (VIX) was set up in 1996 by the Vienna University Computer Center to support the exchange of packets (also often called "peering") amongst those ISPs that had already started in the early 90ies to offer Internet services to customers in Austria: ACOnet, APA, EUnet GmbH, IBM Global Network and VIAnet. Over the years many other ISP joined in.

The basic motivation for creating the exchange point was threefold:

  • to avoid loading expensive wide-area connections by keeping local IP traffic as local as possible,
  • to improve the overall performance of the inter-ISP connections, and
  • to minimize delays when handing over packets to a different service provider.

By 1999 the VIX was already occupying 5 full racks of equipment in the NIG ("Neues Institutsgebäude" of the University of Vienna) and interconnecting 33 ISPs. The exchange point hardware itself was simply a regular Ethernet switch (brand: Cisco). At that size various bottlenecks became more and more obvious. Later during the year the service was relocated to a dedicated area. This room was properly set up with air conditioning, USV, 21 full-sized racks and improved access control. The switching hardware was upgraded to support Fast Ethernet (brand: Cisco).

By 2001, 70 Internet Service Providers were present at the VIX. Amongst them were some well-known internationally active ISPs, e.g. Deutsche Telekom and Cable&Wireless (USA). This rapid growth required planning for another extension in order to accommodate new participants and to handle the increasing amount of traffic by installing more powerful switching hardware. At the Vienna University "NIG" location, both the human resources and the physical space were by far too limited to allow for another increase in the number of racks and for maintaining the additional equipment. To get around this limitation a second location was sought.

Interxion, a company operating data centers in many locations throughout Europe and having a PoP (Point of Presence) in Vienna was able to meet the requirements. In particular, Interxion is not competing with ISPs in the field of commercial Carrier or Telecom Services or in IP Business Services. Thus the commercial neutrality of VIX was preserved, the physical space limitations were removed and location redundancy was offered for the first time.

Together with the provisioning of the second location a couple of major investments had to be made:

  • First of all the seasoned switching hardware was replaced and two new switches were put into production which were able to support connections at 1 Gigabit/s speed (brand: Extreme Networks).
  • Secondly, connectivity between the switches at the two exchange point locations was implemented by installing two separate pairs of dark fiber which are routed along completely separate physical paths.

In retrospect, the decision to sign a contract with Interxion proved to be a perfect choice, as the collaboration since 2001 has always been very smooth and successful.

In parallel with working on implementing IPv6-based services for the Vienna University itself, and within ACOnet, the VIX started to offer support for exchanging IPv6-encoded packets between interested ISPs. In order to prevent interference with the IPv4-based production traffic, the IPv6-related connections were configured to use a dedicated VLAN. As IPv6 technology became more and more mature and operationally stable, the separate VLAN was retired. Since the beginning of 2005 ISPs are welcome to configure both IPv4 and IPv6 on their regular connections as a production service.

During 2005 another upgrade of the switching performance became due. By early 2006 the new equipment became fully operational in both locations (without interrupting the switching service during the transition) and the switches are able for the first time to support connections of up to 10 Gbit/s (brand: Foundry Networks). In order to support the continuous increase in traffic, the interconnection between the two locations was upgraded to 2 x 10 Gbit/s.

As of 2006, the level of traffic across the exchange point was in the range of 1 Gigabyte per second, adding up to approximately 100 Terabyte per day. On a more general aspect, the amount of traffic exchanged roughly increased by a factor of 2 per year.