How much does the shielding layer of a data center switch contribute to RS (Resistance Level) improvement?

The shielding layer of data center switch cables makes a significant contribution to improving radiated interference immunity (RS). A properly terminated shield can provide a 20-30dB improvement in immunity. The principle is that the shielding layer short-circuits interference current to the chassis ground instead of flowing into the signal line. In actual tests on the same model, unshielded twisted-pair (UTP) cable exhibited bit errors at a 10V/m field strength, while shielded twisted-pair (STP) cable with 360° grounding passed the 30V/m test. Design specifications: RJ45 connectors should use shielded metal-shell connectors; the impedance between the shielding layer and chassis ground should be <5mΩ, crimped using conductive foam or metal springs; chassis ground and signal ground should be bridged at a single point using a 1nF/2kV capacitor. Etymotic recommends using the CMZ2012A-900T common-mode inductor for enhanced common-mode rejection.