Ethernet Pinout Standards

IP cameras and other network devices commonly use an Ethernet connection with a standard RJ45 connector, following one of two widely recognized wiring schemes:

T568A – preferred in residential installations and is the standard for federal government projects in the U.S.
T568B – commonly used in most commercial installations in the U.S.

These standards specify the order of the eight (8) colored wires inside the Ethernet cable, ensuring reliable data transmission and Power over Ethernet (PoE) support.

**IMPORTANT: Always use the same standard on both ends of the cable (i.e., T568A-to-T568A or T568B-to-T568B) to avoid wiring mismatches. Only use two different wiring standards on the same cable when making a crossover cable, which is a rare need with modern auto-sensing network devices.

T568A and T568B Standards

T568A and T568B are both part of the TIA/EIA-568 standard, which regulates the wiring of twisted-pair network cables. Both standards function virtually the same, with the primary distinction between them being the color arrangement of the wire pairs.

T568A Standard

Pair 1
- Pin 4 – Blue (Unused/PoE)
- Pin 5 – White & Blue (Unused/PoE)
Pair 2
- Pin 3 – White & Orange (Receive +)
- Pin 6: Orange (Receive –)
Pair 3
- Pin 1 – White & Green (Transmit +)
- Pin 2 – Green (Transmit –)
Pair 4
- Pin 7 – White & Brown (Unused/PoE)
- Pin 8 – Brown (Unused/PoE)

T568B Standard

Pair 1
- Pin 4: Blue (Unused / PoE)
- Pin 5: White/Blue (Unused / PoE)
Pair 2
- Pin 1: White/Orange (Transmit +)
- Pin 2: Orange (Transmit -)
Pair 3
- Pin 3: White/Green (Receive +)
- Pin 6: Green (Receive -)
Pair 4
- Pin 7: White/Brown (Unused / PoE)
- Pin 8: Brown (Unused / PoE)

Transmit and Receive

The terminology “Transmit” and “Receive” are usually associated with the computer or switch. However, on the camera or network device itself, these roles are internally reversed.

Camera as a Data Source (Transmitter)

The camera is transmitting video or image data to a destination (server, monitoring system, or recording device).
This is the camera sending its output, acting as the transmitter of data.

Camera as a Networked Device (Receiver)

The camera itself, as part of a network, is also receiving commands and configuration from other devices.
These can include network settings (e.g., IP addresses), control commands (e.g., PTZ), and firmware updates.

Examples:

Transmitting – a camera is sending a video stream to a monitoring station. In this case, it is acting as the transmitter of the video feed.
Receiving – a camera is receiving settings or control instructions from a central management system, telling it to adjust or change streaming protocols. In this case, it is acting as the receiver of network commands.

Power Over Ethernet (PoE) Support

IP cameras commonly receive both data and power through the same Ethernet cable using Power over Ethernet (PoE), in compliance with 802.3af/at/bt standards, using two main PoE methods:

Mode A (Endspan) – power is delivered over the data pairs (pins 1, 2, 3, and 6).
Mode B (Midspan) – power is delivered over the spare pairs (pins 4, 5, 7, and 8).

Most modern PoE switches and injectors can detect and provide the required voltage wattage for the connected device.

Replacing Ethernet Cables

When replacing Ethernet Cables for your IP cameras:

Verify and notate your infrastructure’s wiring standard (T568A or T568B) to remain consistent.
Use high-quality Cat5e or Cat6 cable for optimal signal and power delivery.
Test the cable using a cable tester to confirm proper pinout and continuity.
If you are using PoE, ensure that your PoE switch or PoE injector meets the camera’s power requirements.
- 802.3af = 15.4W
- 802.3at = 30W

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