**2.2 International connectivity**

NKN is connected to the Pan-European Research network, GÉANT (www.geant.net), by means of a 2-5 Gbps link co-funded by Government of India and the European Commission within the framework of the TransEurasia Information Network project phase 3 (TEIN3, http://www.tein3.net). TEIN3 provides Internet network to the research and education communities in the Asia-Pacific area serving more than 8000 research and academic centre and 45 million users. TEIN3 includes 19 partners and rely on four hubs: Mumbai, Singapore, Hong Kong, Beijing (see Figure 4). For India TEIN3 provides a 2.5 Gbps link from Europe to Mumbai and also a 2.5 Gbps link from Mumbai to Singapore.

Applications Exploiting e-Infrastructures Across

Fig. 4. GARUDA Grid and WLCG Tier2 sites

**2.3.1 The Worldwide LHC Computing Grid in India** 

WLCG represents the world largest grid infrastructure and with the start of data taking at the CERN Large Hadron Collider (LHC) WLCG entered the full production phase (Bonacorsi, 2011). The data from the LHC experiments will be distributed around the globe, according to a four-tiered model. India participates with two Tier2 centres supported by the Department of Atomic Energy (DAE). One at the Tata Institute for Fundamental Research (TIFR) Mumbai provides the services for the CMS experiment. The other one, dedicated to the ALICE experiment, is located in Kolkata and managed by the Saha Institute of Nuclear

These Tier2 centres provide access to CMS & ALICE users working from Tier III centres of Universities and national labs and LCG Data Grid services for analysis. TIFR is presently connected to CERN with the 2.5 Gb/s TEIN3 link via NKN. The ALICE TIER2 centre is also connected via NKN at 1 Gb/s. Thanks to a coordinated action of the main actors involved

Physics in collaboration with the Variable Energy Cyclotron Centre (VECC).

Europe and India Within the EU-IndiaGrid Project 289

Fig. 4. TEIN3 Topology

In this vision, for research collaborations, Mumbai represents, at the same time, the Gate of India and the gateway to Asia-Pacific area.

In addition it is under way an agreement to connect the Open Science Grid in the USA in cooperation with the USA National Science Foundation and to connect to Japan a dedicated high speed link from Chennai. The NKN-TEIN3 connectivity is successfully exploited by several research applications as described in the sections below.
