is to be routed in the particular case of an afdx switch it also carries out before the routing all sorts of consistency checks this is particularly the case with the frame policing function which aims at guaranteeing and if necessary at limiting the bandwidth associated with each of the virtual links vl corresponding to the calibrated data flows between systems by deleting frames violating the bandwidth budget allocated to a definite data flow this frame policing function is also parameterized by configuration tables loaded by the monitoring computer during an initialization phase for the requirements of the mib constitution it is usual for the digital interface devices or mac layers associated with each of the bidirectional ports of the switch to have a battery of counters designed so as to accumulate over a short duration typically one second the number of events or the quantitative variables associated with the information flow being processed that will be acquired in a period of the same order by the manager constituting the mib a non exhaustive list of the types of quantities thus gathered is provided below by way of example number of ethernet frames transmitted without errors by a given port number of ethernet frames received without errors by a given port numbers of errors having caused the transmission of a frame to be abandoned number of crc errors having caused the reception of a frame to be abandoned number of errors in length having caused the reception of a frame to be abandoned it is noted that having available all.