Telecommunications, Data, and Network Cabling
This domain tests structured cabling and the networking concepts a field technician must apply. Know the twisted-pair categories (Cat 5e, 6, 6A, 8) and their frequency and distance limits, the 100-meter channel rule (90 m horizontal + 10 m of patch cords), and why Cat 6A supports 10GBASE-T to full distance while Cat 6 is limited. Understand shielded versus unshielded cable and proper shield bonding at one end as designed. Know fiber types - multimode (OM3/OM4/OM5) for short reach and singlemode (OS2) for long reach - and connector families (LC, SC, ST) plus polish types.
Termination and testing matter: T568A versus T568B wiring, the need for consistency within a project, and what a certification tester reports - wire map, length, insertion loss, NEXT, return loss, and for fiber, loss and polarity. Understand PoE standards and power budgets, since PoE drives many low voltage devices. Know basic network topology and device roles (switch, router, patch panel, media converter) and the purpose of VLANs for separating devices such as cameras and access control from office traffic.
Traps: mixing up T568A/B pinouts; assuming a continuity tester proves performance (it does not - certification is required); forgetting that a "passing" link can still fail PoE due to resistance and heat in bundles; and confusing multimode with singlemode distance capability. Also expect questions on cable management and labeling.
Worked rule of thumb: always test to the standard the project specifies, save the report, and re-test after any re-termination. For PoE, verify voltage at the device under load, not open-circuit.