Implementing the L1 trigger path

This note discusses two issues which have emerged recently related to the transmission of data to the DAQ system by the L1 Front-End electronics and the implementation of the L1 trigger path. Firstly the note describes a scheme to centrally broadcast the IP destinations for the L1 data channel and the High-Level Trigger channel. The scheme is already supported by the TFC system, in particular by the current version of the Readout Supervisor "ODIN". Secondly, the note discusses the consequences of eliminating the L1 Trigger Sorter module located between the L1 trigger processing in the CPU farm and the TFC system. Two possible implementations are described: sorting the L1 triggers in the Readout Supervisor "ODIN" or handling unsorted L1 triggers fully. The two solutions require a redesign of the Readout Supervisor which implies a delay of about one year with respect to the current planning. However, the current version can still be used for tests and in the experiment provided a provisory L1 Trigger Sorted module exist.