TL;DR: The RJ45 jack (the female socket / 母座) is the fixed half of the link — its orientation is locked in at layout. None of the orientation options change the pinout (IEC 60603-7 + T568A/T568B handle that). You're only choosing mechanics. Pick deliberately:
- Tab-down vs tab-up -> which way the latch + LEDs face. Tab-down = LEDs on top (normal front panel). Tab-up = inverted board.
- Right-angle (horizontal) vs vertical -> cable parallel to the board (board-edge front panel) vs perpendicular (stacked / height-limited).
- THT (DIP) vs SMT -> through-hole = stronger retention for high-churn ports; SMT = automated assembly + lower profile.
- Board-mount vs panel-mount -> PCB socket vs enclosure feed-through (keystone, coupler, sealed waterproof).
- Special footprints -> offset (reverse-mount), low-profile (low height), stacked 1×N / 2×N for port density.
Gotcha: vendor "90°/180°" labels are NOT standardized. Read cable-entry direction off the mechanical drawing, verify the panel cutout.
Sourced data point: VOOHU's 1×1 tab-down through-hole integrated magjacks are rated 750 mating cycles min, 23 N max mating force. VOOHU makes the socket side in every orientation (standard, offset, low-profile, integrated magjack, waterproof).
Full write-up (selection table + common mistakes): https://voohuelectronic-ux.github.io/voohu-rj45-guide/resources/rj45-jack-orientation-tab-up-vs-tab-down.html
