Networking · VISUAL GUIDE
PoE cable pairs: an important clarification
The image states that PoE uses spare pairs. That statement must not be treated as a general rule.
What the image shows
The image states that PoE uses spare pairs. That statement must not be treated as a general rule.
How to interpret it
PoE can use different pair sets depending on the variant and equipment. In Gigabit Ethernet all four pairs carry data; power can coexist with data signaling. IEEE 802.3bt supports four-pair power delivery.
What to check before installation
Do not separate conductors or improvise a connection based only on this illustration. Use compatible equipment and check the switch and powered-device documentation.