2002 - cesnet

Figure 7.1: Grid nodes for SC2002and Abilene networks. Instead of a reserved IP service, we decided to makeexperimental use of the LBE (Less than Best Effort) service, which allows fordata to be sent with maximum speed (without protection from congestion), andthe network itself will drop out some data in case that the line gets overloaded.The application made use of the UDP protocol and the used real-time visualizationis not actually prone to occasional data dropouts (human eye is not ableto notice short-term dropouts, while long-term dropouts can be approximatedthanks to data from other sources).Thanks to help of the CESNET operating team, we installed a three-port GEcard in the PoP node of CESNET2 in Brno, and connected it with the cluster,which thus reached a theoretical external connectivity of 4 Gbps. In addition,we temporarily upgraded the Prague–Frankfurt international link to 2 Gbps.Within the experiment, the team succeeded in generating a persisting flow of2 Gbps between Brno and Baltimore, over a period of two hours (for the load ofCESNET2 lines, see Figure 7.2). This represented almost 12 % of the data flow of16.811 Gbps with which the team won.7.3 Users and ComputationFor a complete review of users, distribution of the utilization of MetaCentrumand other parameters, see the MetaCentrum Yearbook for the year 2002, whichwill be issued during the first half of the year 2003. At present, only the Meta-Yearbook 2001 11 is available; however, the overall trends are similar to those in2002.At present, MetaCentrum has approximately 200 active users, administered inthree administration nodes at ZČU, UK and MU, roughly at a ratio of 1:2:3. Thebiggest users are members of the Czech Academy of Science and MU Brno11http://www.meta.cz/yearbooks/High-speed National Research Network and its New Applications 2002101