History of National Research and Education Network

20 years of CESNET


Publication released on the occasion of 20th anniversary of the CESNET association. It compiles the most important activities and achievements in our history (PDF, 5 MB).

Here we provide a short overview of the development and most important events in the history of National Research and Education Network of the Czech Republic.


First steps of academic networking in the Czech Republic lead to 1991 when—thanks to an academic initiative of the IBM company—an IBM mainframe was installed in the computing centre of Czech Technical University ion Prague and connected to the EARN (European Academic Research Network). The interconnection with a bandwidth of 9.6 kbps was of local availability only but it was the first possibility to acces a world-wide network in our country.

On the beginning of 1992, the bandwidth grew to 19.2 kbps and the interconnection was split to two independent channels—one for EARN and another one for Internet. The official launch of Internet in the Czech Republic took part at 13 February 1992.

There was a demand for Internet access in the academic community. Representatives of universities and the Academy of Sciences met since 1991 and discussed technical solution of a network to interconnect these organisations. It resulted to a project named FESNET (Federal Education and Scientific NETwork) submitted in 1992 to the Fund for dynamic development of universities provided by the ministry of education.

Approaching split of former Czechoslovakia to two independent countries led to a modification of the project. Slovak part of the network was removed and the remaining project was renamed to CESNET (Czech Scientific and Education NETwork). Ministry of education allocated the financial resources and the CESNET network started ist operation on the beginning of 1993.

1993: CESNET – first academic network of the Czech Republic

Parameters agreed with contemporary technology. Most lines operated at 19.2 kbps, only the Prague–Brno backbone started at 64 kbps. Huge demand brought rapid growth of bandwidth.

The original CESNET network was not exclusively academic. It connected commercial organisations to improve operational costs.

Establishing of the CESNET association and TEN-34 CZ network

The team responsible for backbone operation worked at the computing centre of the Czech Technical University in Prague. This ordering became inconvenient for many reasons. In consequence, universities and the Academy of Sciences agreed on creation of separate subject ensuring the necessary network operation. The CESNET association was constituted on 6 March 1996. Founding memeber were 26 Czech univerzities and the Academy of Sciences of the Czech Republic.

Newly established association entered in the preparation of the European TEN-34 project immediately. Aim of the project was to create an European academic infrastructure comparable to academic networks in USA. Participating countries should build similar national infrastructures. In the Czech Republic, TEN-34 CZ project supported building of such network and the CESNET association executed it.

TEN-34 network was developed in 1997 and provided 34 Mbs bandwidth whci was unique at that time. There was a restrictive acceptable usage policy of the network which allowed to connect solely organisations (or their parts) engaged in science, research, development and/or education. The CESNET association operated two separated networks: TEN-34 CZ (academic) and CESNET (commercial to support funding).

1997: TEN-34 CZ – ATM backbone at 34 Mbps

TEN-34 CZ served well its users and grew continuously. Prague–Brno backbone was improved to 155 Mbps in June 1998. Similar changes on the international level followed soon.

European TEN-34 project ended in 1998. New project named Quantum followed to build the TEN-155 network based on ATM technology with 155 Mbps bandwidth. New generation of European backbone was put to operation on the end of 1998. CESNET was involved again and renamed its academic network to TEN-155 CZ.


1999: TEN-155 CZ – ATM at 155 and 34 Mbps

The whole network was based on ATM. Next year we experienced first step signalling a technology change. We deployed experimentally the 2.5 Gbps PoS technology on the line Prague–Brno in January 2000. ATM was unable to reach comparable bandwidth.

2000 was a very important milestone in our history. Regarding the contemporary situation on the Internet connectivity market, we decided to close our commercial network and focus exclusively on the development of the national research and education network. We signed a contract with the Contactel company in March 2000. The CESNET network ceased its existence by this because Contactel included it into its infrastructure.


Another European project was launched in 2000 to ensure further development of European backbone. The GÉANT project aimed at gigabit bandwidth.

2001: CESNET2 – first gigabit lines

We started our preparation for gigabit deployment too. But this required a change the transmission technology as well as data transmission philosophy in general. We leased fixed transmission capacities up to this time. But there were no gigabit transmission services available on the market and their introduction would be extremely expensive.

In consequence, we pioneered the Customer Empowered Fibre Network (CEF) approach. This approach builds on “dark fibres”—a passive fibre infrastructure which activation ensures the user itself by its own devices. CEF is more demanding on the user (regarding skills and funding) but from our point of view it was clearly more efficient.

The CEF concept succeeded and was deployed in the whole network core in following years. In October 2001 we renamed the new generation network to CESNET2. The network provided gigabit capacities in the most important backbone nodes since 2002 and continuously increased availability of real high-speed transmissions. This development phase was funded by the research intent named High-speed national research network and its new applications supported by Ministry of education form 1999 to 2003.

Optical technology

New technological phase defined by the deployment of DWDM began in 2004. It was the major focus of our new research intent named Optical national research network and its new applications (2004–2010). DWDM enables to carry several independent signal over single optical fibre which opens new possibilities for the backbone infrastructure. Common traffic can be separated from experiments, demanding applications can get dedicated channels (so-called end-to-end services).

First DWDM line interconnected Prague and Brno in 2004. Backbone ring Prague–Brno–Olomouc–Hradec Králové–Prague was finished one year later. It provided redundant interconnection with capacity up to 32 channels.


2005: CESNET2 with DWDM core

We expanded DWDM gradually to further parts of the network and constructed extensive DWDM infrastructure. Considering the very high pricing of commercial DWDM equipment we decided to start an in-house development of optical components – the CzechLight series of devices. We started by optical amplifiers and gradually developed more sophistiated components like optical switches or add/drop multiplexers.

CzechLight devices are manufactured under our license and available on the market. Their favourable economical parameters enable to deploy them to many lines of the CESNET2 network which allowed to provide DWDM in smaller nodes where the deployment of commercial devices would not be cost-effective.

On the end of 2010, there were more than 1400 km of optical fibres lit by the Cisco ONS 15454 commercial devices and more than 2600 km carried on by the CzechLight DWDM devices. For comparison: perimeter of the Czech Republic id approximately 2300 km.

2010: Rich DWDM infrastructure in CESNET2

Upgrade to 100 Gbps

Growing volume of data transmissions and development of applications with extreme demands for data flows raised the need to upgrade the network backbone to a higher bandwidth. First exeriments with 100 Gbps came true in 2011 and 2012. We performed several tests of capability of our optical infrastructure to carry such transmission speeds.

Real deployment occured in 2013 – first lines were upgraded early in 2013 and the complete CESNET2 core was upgraded to 100 Gbps until the end of June. The same capacity was deployed to our interconnection with GÉANT in 2015.


2015: CESNET2 100 Gbps core

Last change: 21.4.2018