How should surge differential mode protection be designed for data center switch ports?

Data center switch network ports face the threat of induced lightning surges and must meet the IEC61000-4-5 Level 4 differential mode ±2kV test requirements. The protection solution uses a Yinte Electronics SMBJ58CA TVS (VRWM=58V clamping voltage 93.6V peak pulse power 600W) connected in parallel to the differential line to ground. The SMB package of this device meets the requirements of PoE++ 90W power supply scenario without false triggering. It is used in conjunction with a CMZ2012A-900T common mode inductor (90Ω@100MHz DC resistance 0.3Ω) to suppress common mode surge residue. After a 4kV surge, the PHY chip works normally with a packet loss rate of <0.001%. The PCB layout requires the TVS to be close to the RJ45 connector with a trace length of <3mm and a grounding via diameter of 0.3mm×2.