Innovative Networking Technologies





The LHCOPN is a 10Gbps star-structured network infrastructure that interconnects the globally distributed Tier-1 centers and CERN (Tier-0). This infrastructure is primarily for transportation of about 12 petabytes/year data of the LHC project up to the Tier-1 centers. Redundancies within the LHCOPNs are designed to intercept link failures and to allow international Tier-1 communication.



o   First connection GridKa - CERN

From the early beginning the Steinbuch Centre for Computing is one of the partners of the collaborative network LHCOPN. Since the first LHCOPN meeting in Amsterdam (March 2003) the SCC is actively involved in planning and development and plays a leading role in further development. Together with the DFN (German Research Network) the first connection between GridKa (German Tier 1) and CERN (Tier-0) was established as a 1Gbps routed interconnect.


o   Layer-2 Evaluation Project

Furthermore, under the DataTAG project between November 2003 and February 2004, a Layer-2 triangle has been set up between CERN, GridKa and CNAF. In this testbed a layer-2 network was evaluated, which combines multiple Tier-1/0 centers on a VLAN to each other. 

The setup of the network was relatively complex because layer-2 switching connections had to be established over MPLS between the national research networks.

However there was no increase in transmission speed (latency, and connection setup). Therefore this concept of summarizing several Tier 1/0 centers in one layer-2 domain has been dropped.


o   Different steps

In October 2004 the first step towards a 10Gbps connection within the LHCOPN to GridKa was done. For this purpose a new routed link was established over the advanced DFN infrastructure (X-Win). About one and a half years later, in March 2006 a point to point (Layer 2) connection between CERN and GridKa was realized as a dedicated wavelength (lambda)..

The routed 10 Gbps X-Win uplink was further used for exchange of data with the German Tier 2 centers.


  Today's structure

o   Infrastructure

In the current expansion of LHCOPN the SCC runs 4 * 10 Gbps point to point links between GridKa and CERN, FR-CCIN2P3 FR, NL-T1 and IT-INFN-CNAF. In addition to the LHCOPN project GridKa has a 10Gbps connection to the Layer-3 network X-Win (DFN core backbone). Through this connection the German Tier-2/3 centers exchange data with the Tier-1 center GridKa. In addition there exist two other direct 1Gbps links to European centers FZU (Prague) in the Czech Republic and the Polish centers in Warsaw, Krakow and Poznan.


Overall the LHCOPN connects the Tier-1 centers which are involved in the LHC collaboration and CERN (Tier-0), providing additional redundancies to prevent loss of connectivity in case of link failures.

o   Routing protocols

As shown in the following figure routing within LHCOPN is realized by BGP.