8 pin RJ45 (8P8C) female connector at the hub.
8 pin RJ45 (8P8C) male connector at the cable.
Power over Ethernet (PoE) is a technology, described by IEEE 802.3af standard, that allows IP telephones, wireless LAN Access Points, Security network cameras and other IP-based terminals to receive power, in parallel to data, over the existing CAT-5 Ethernet infrastructure without the need to make any modifications in it.
PoE integrates data and power on the same wires; it keeps the structured cabling safe and does not interfere with concurrent network operation. The original 802.3af standard delivers a nominal 48 V DC over unshielded twisted-pair wiring, providing up to about 12.95 W at a powered device. Later standards raised this considerably: 802.3at (PoE+, 2009) provides about 25.5 W, and 802.3bt (PoE++, 2018) up to roughly 71 W at the device by using all four pairs.
| Pin | Alternative A | Alternative B |
|---|---|---|
| 1 | Vport Positive | |
| 2 | Vport Positive | |
| 3 | Vport Negative | |
| 4 | Vport Positive | |
| 5 | Vport Positive | |
| 6 | Vport Negative | |
| 7 | Vport Negative | |
| 8 | Vport Negative |
POE pinouts from different manufacturers
| STANDARD | SOURCE | LOAD | REMARKS |
|---|---|---|---|
| Ethernet RJ-45 connector pin number | |||
| Source Voltage | 1 | 2 | 3 |
| IEEE 802.3af using data pairs | 48 V DC, protected | RX, DC+ | RX, DC+ |
| IEEE 802.3af using spare pairs | 48 V DC, protected | RX | RX |
| Intel, Symbol, Orinoco | Usually 12 or 24 V DC | RX | RX |
| Cisco (OLD old standard) | 48 V DC | RX | RX |
| Cisco (NEW old standard) | 48 V DC | RX | RX |
| D-Link (Adapter) | 48 V DC | RX | RX |
| Apple MacIntosh AirPort PoE, Extreme | 48 V DC | RX | RX |
| HyperLink | Many DC Voltages Available | RX | RX |
| NYC Wireless “Roll Your Own” | 12 or 24 or 48 V DC | RX | RX |
PoE - powered devices should obey following specifications:
| Parameter | Min | Max |
|---|---|---|
| Signature Resistance, KOhm | 23.75 | 26.25 |
| Startup Time (till I>10mA), ms | 300 | |
| Power Consumption, W | 12.95 | |
| Operating Input Voltage Range, V | 36 | 57 |
| Must Turn on Voltage, V | 44 | |
| Must Turn off Voltage, V | 30 V | |
| Input Current (@36Vdc), mA | 10 | 350 |
| Input Current, Peak, mA | 400 |