Does the conducted interference from data center switches meet Class A or Class B standards?

Data center switches must meet different conducted interference limits depending on the application scenario: EN55032/GB9254 Class A (industrial environment limits) is applicable for enterprise-level data centers, but an increasing number of cloud data centers require compliance with Class B (residential environment limits) for hybrid deployment compatibility. Etymotic's matching filtering solutions can simultaneously meet both standards: Class A design uses a single-stage common-mode inductor CMZ7060A-701T + 0.22μF X capacitor + 1000pF Y capacitor; Class B requires two-stage filtering, adding a second-stage common-mode inductor CMZ3225A-501T (500Ω@100MHz) and increasing the Y capacitor to 2200pF. Actual measurements show that the Class B solution has 12-18dB higher insertion loss than the Class A solution in the 0.5MHz-5MHz frequency band.