The physics potential comes at a price. The experimental environment at the LHC is characterised by a high luminosity,10³⁴cm^-2 s^-1, a high bunch crossing rate, 40 MHz, a large background from minimum bias events and QCD-jets, and very high levels of radiation. Therefore stringent requirements are imposed on the performance of the detectors at the LHC.

The trigger and data acquisition is an area where the high bunch crossing rate and large data rates are particularly felt. The second level trigger has been modelled by a "paper model" to compare the different architectures proposed. The results have shown bottlenecks in the system which were not originally foreseen and have revealed important aspects of the data traffic in the system.

A possible technology for the level-2 interconnects is Fast Ethernet. A study of the feasibility of using this technology was carried out in the light of the modelling results.