An Investigation into Transport Protocols and Data Transport ...

2.3. Data Volumes and Regional Centres 33
Year Production Experimental
2001 0.155 Gbps 0.622-2.5 Gbps
2002 0.622 Gbps 2.5 Gbps
2003 2.5 Gbps 10 Gbps
2005 10 Gbps 2-4×10 Gbps
2007 2-4×10 Gbps 40-100 Gbps
2009 40-100 Gbps 5×40 Gbps or 20-50×10 Gbps
2011 5×40 Gbps or 20×10 Gbps 25×40 Gbps or 100×10 Gbps
2013 Terabit Multi-Terabit
Table 2.1: The expected traffic volumes of the ATLAS LHC Experiment compared
to that of commodity Production volumes [New05].
which connects the US and Centré Européenne pour la Recherche Nucléaire
(CERN) has grown from a 9.6Kb/sec link in 1985 to a 10Gbit/sec link today.
The predicted network resource requirement of the ATLAS experiment is
shown in Table 2.1. It shows that within ten years of expected data collection
at the LHC, the amount of data expected to be transfered per year will grow
from petabytes to extabytes of traffic per year.
The flow of the data from the detector to physicists must be well coordinated.
The MONARC [LN00] group defines a hierarchy of Tiers from which
the data stored at the facilities at a detector should be distributed around
the world for storage and processing of these huge datasets.
The member sites of LHC experiment are categorised into Tiers, depending
on their ability to supply data to the user. The intention is that the total
resources at each Tier will be approximately the same. The figures quoted
here are for ATLAS, and similar resources will be needed by the other LHC
experiments. The Tiered hierarchy is shown in Figure 2.1, which also shows
the expected traffic volumes between Tiers.
• Tier-0