How to suppress conducted interference at the communication interface of an edge computing box?

For edge-mounted communication interfaces such as Ethernet, USB, and RS485 cables, which can be several meters long, they are prone to becoming conducted interference antennas. The preferred suppression measure is to connect a common-mode choke in series with the interface. For example, for gigabit Ethernet ports, a CMZ2012A-900T is recommended. Its name is CM common-mode Z, impedance 2012, size 2.0×1.2mm, 900T impedance 90Ω, 100MHz, effectively filtering common-mode current. Secondly, for low-speed interfaces, a PBZ1608E600Z0T ferrite bead can be connected in series. This ferrite bead is named PB ferrite bead Z, common 1608, size 1.6×0.8mm, E600 impedance 60Ω, Z tolerance 0, internal code T, packaged and mounted near the connector on the signal line. Simultaneously, an LC filter grounding inductor is used for the interface ground. A CML3225A-101T is recommended. Its name is CML common-mode inductor 3225, size 3.2×2.5mm. The 101T inductance of 100μH presents high impedance at high frequencies, forcing noise backflow to the source end. Through this combination, the conduction interference at the edge box communication interface can be attenuated by 20dB below 30MHz, meeting the requirements of EN55032 Class B.