The University Computing Centre of the University of Zagreb (Srce) has launched a new location of the Croatian Internet Exchange (CIX) at the DC North data center in Varaždin.
The Croatian Internet eXchange (CIX) is Croatia’s central hub for internet traffic exchange. It was established and has been hosted by Srce since 2000, with its network infrastructure gradually distributed across multiple locations over the years. In 2016, a second CIX location was established in Zagreb at the Digital Realty ZAG1 data center, and the launch of the third location in Varaždin is the result of a hosting agreement signed between Srce and DC North in October 2024.
“With the further distribution of the CIX network infrastructure, we aim to achieve greater resilience and availability of CIX, providing CIX members with even better service quality as well as reliability and flexibility.”, said Director of Srce, Ivan Marić.
CIX is open to all internet service providers (ISPs) in the Republic of Croatia. By using CIX, costs are reduced for both ISPs and end users, enabling the highest quality network connectivity via the shortest route within Croatia. Since its establishment, over 1,800 PB of data have been transferred through CIX, with 322.7 PB transferred in 2024 alone—an 8% increase compared to the previous year. Currently, CIX has 38 active members.
The new CIX location offers members the same connection capabilities and service quality as the other CIX sites, with redundant 100 Gbit/s links to the other two locations, and the ability to expand further if member needs grow.
“The DC North data center in Varaždin holds the Uptime Tier III Facility certificate and is strategically located at the northern gateway of Croatia at the crossroads of international optical backbones. It is situated in a different seismic zone than Zagreb and spans 2,000 m² of IT space across six DC rooms, with a total available power capacity of 4 MW. It provides state-of-the-art data center services, strictly adhering to the ‘Carrier-Neutral’ concept.”, added Darko Pintarić, Director of DC North.
Srce, as the initiator and coordinator of CIX since its inception, continuously ensures the technical conditions for interconnection and uninterrupted operation. Last year, the infrastructure was upgraded to provide sufficient capacity for users wishing to upgrade their connectivity from nx10 Gbit/s to 100 Gbit/s. This included a technological step forward with Ethernet VPN (EVPN), which was necessary for the new three-location topology. With CIX’s recent alignment with the Mutually Agreed Norms for Routing Security (MANRS), Srce has made another contribution to a more secure internet.
Since 2008, CIX has been a full member of the European Internet Exchange Association (Euro-IX), which promotes a culture of open exchange of ideas and experiences among its members.