How many wires does PoE use?

how many wires does poe use?

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Did you know that network cables, like Cat 5e and Cat 6, are made up of eight wires arranged as four twisted pairs? In 10 and 100BASE-T Ethernet, two of these pairs are used to send information and are known as the data pairs. The other two pairs are not used and are called the spare pairs. However, Gigabit Ethernet uses all four pairs.

However, we can divide the Ethernet port into multiple categories based on its types. And each sort of Ethernet cable would have different features. The Cat6 and above versions of Ethernet ports have other numbers of wires, while the performance of the Ethernet cable below has different twisted pairs of copper wires.

This article will elaborate on the total number of Ethernet cables and the Power over Ethernet PoE.

What is Power over Ethernet (PoE)?

Have you heard of Power over Ethernet PoE? If yes, maybe you have some previous knowledge. If you don’t know anything about Power over Ethernet, let me explain it here.

Power over Ethernet (PoE) is a networking technology that utilizes the Ethernet cable to support:

In early 2000, this technology emerged as the developing solution for power supply, delivering electrical power to IP cameras, laptops, and even high-power flat screens.

A question remained unanswered. Do you know what that question is? Why use PoE for power and data connection?

There are many reasons for this question. First, PoE stimulates high power of up to 100 watts, which is impossible with other technologies. At the same time, you are achieving a data connection that is also in Gigabit speed. Isn’t it enough?

So, Power over Ethernet PoE will charge the high-powered devices and connect them to VLANs simultaneously. Behind this fact, we are highly dependable on Power over Ethernet PoE for all types of electrical power supplies.

Suggested Reading: What is PoE?

Three standards upon which PoE relies

Every system, whether WiFi or PoE, requires working principles. Based on those standards, they deliver the relevant applications. As far as we know about power over Ethernet PoE, the Institute of Electrical and Electronics Engineering (IEEE) has defined three fundamental standards.

Suggested Reading: What is PoE Standard?

Here are PoE standards.

PoE 802.3af

It is the earliest PoE standard introduced in 2003. This standard provides both power and a data connection. The crucial point is its lower electrical power supply.

However, I have listed the unique specifications of PoE 802.3af.

  • It uses two pairs of twisted copper wires in an Ethernet cable to deliver power to a powered device.
  • The maximum power available to the powered device is 12.4 watts, while the full power per port is 15.
  • It can support wireless access points, surveillance cameras, VoIP phones, etc.

It is not used very often because of its few applications and low power. However, you can find its applications in smaller networks.

PoE 802.3at

The 15 watts of power is nothing regarding high-power devices. It is where the IEEE felt concerned about increasing the total power of the PoE.

2009, they upgraded the Power over Ethernet standard to the PoE 802.3at. It has more power and data speed.

Do you know the best thing about the PoE? They are backward compatible. To elaborate on PoE 802.3at, I have listed salient features below:

  • Two pairs of twisted copper wire in the Ethernet cable make up the port for the PoE 802.3at standard.
  • The maximum power available to the device is 25.5 watts; at the port, you get 30 watts.
  • It can support PTZ IP cameras, video IP phones, and alarm systems.

It is still used in most networks, especially surveillance systems with fewer power requirements.

Suggested Reading: What is PoE 802.3at?

PoE 802.3bt

It is the latest PoE standard undergoing upgrades. Finally, we have two types of PoE standards.

This standard revolutionized PoE technology in 2018. It can power high-power flat screens, laptops, and other devices. Therefore, this PoE standard can expect better functionality and power functions.

Here are crucial aspects of PoE 802.3bt.

  • It delivers 100 watts of power. Such high power would be sufficient for large devices and power-sourcing equipment.
  • Four pairs of twisted copper wires in the Ethernet port are requirements to operate this PoE standard.
  • There are two types: PoE Type 3 and PoE Type 4, which offer different power sources for power-sourcing equipment.
  • It can work with high-power tools and resources, especially in the industrial Ethernet system.

It is widely operated in all IT sectors. IT, enterprises, and industrial areas have brought innovation to their systems through this technology.

Suggested Reading: What is PoE BT?

Three steps to construct a PoE network

Do you want to build a PoE network? There are many requirements for it. You must understand the network’s number of switches, technology, and devices.

What you need for a PoE network is here:

One crucial point to be mentioned is that your devices must be PoE-compatible. Otherwise, you have to use the PoE injectors to make them compatible.

If you have all the tools, here are three fundamental steps for integrating and developing a PoE network.

Step 1: Set up All the equipment

The first step is to set up all the tools in place. Ensure you have all the equipment compatible and ready. For example, if you are setting up a surveillance system, you must fix your camera outside or inside the room where you need security.

Similarly, you can set up a monitoring system in a room alongside the switch. It is what I want you to understand about the PoE network. All tools must be in place.

Step 2: Link the Ethernet Port to the PoE switch

Is everything fine? If yes, great! You are good to go for linking the tools. First, take your Ethernet port, check whether it has the connector, and build your connection.

You can use the RJ45 connector to insert the plug into the PoE switch. Remember, Ethernet ports have connectors at both ends to build the links among the devices and Ethernet switches.

Step 3: Integrate your device with high Power PoE

Since you need to get the data and power for your devices, it is time to make the final connection. You can connect your switch to the device. This time, the RJ45 connector will be crucial in maintaining the network and supporting the links.

The distance of the power wire is usually 100 meters. If you want to increase the length, especially for long-distance security setups, purchase PoE extenders and use the technology without hassle.

Additional Step: Join the Router

It is not an essential step. Therefore, I have listed it as an accessory point. If your network performance is not up to mark, you can improve it. Do you know how? By employing the routers. Routers are devices that analyze the data packets and reduce the bottlenecks to optimize performance. Some heavy networks, especially in industrial regions, utilize routers to uplevel performance and security.

The total number of Cables Power over Ethernet PoE considers

There are different Ethernet cables. There are multiple types.

  • Category 1
  • Category 2
  • Category 3
  • Category 4
  • Category 5
  • Category 6
  • Category 7
  • Category 8

Twisted pairs of copper wire determine each type of Ethernet port. Some cables have two pairs, some four pairs, and some eight pairs.

Depending on the relevant type, we interpret the Ethernet cable.

So, what is the total number of Ethernet ports in the PoE?

Different factors determine the total number of wires in the Ethernet.

Here are those factors.

Number of Connections

If you have one connection, you only need a single wire that may be four pairs, two pairs, or eight pairs twisted. The total number of connections determines the total number of ports required.

Some PoE networks have layering. For example:

  • Core Layer
  • Access layer
  • Distribution layer

Since all these layers contain different switches, the total switches and number of connections will guarantee accurate requirements for copper cables.

Total devices

Which device do you have? Suppose a surveillance system where you need to set up multiple cameras. If you have 10 IP cameras, you would need 10 Ethernet ports to prevent the overloading of PoE power.

When considering the number of ports, better calculate the total number of devices and relevant other parameters.

Number of switches

The number of switches is an important criterion. Do you know why? Because you need PoE switches to transmit the data over the port. By building the connections, the number of switches will uncover the total number of ports.

Another critical thing to note is that you would require at least ten cables if you have ten switches.

Additional Devices

The number of wires also depends on additional devices, such as routers. If you have one router, it will require at least one Ethernet port. The same goes for more than one router in the bigger and more complex network structures.

So, the exact number of Ethernet ports can not be described unless we know all the factors. After getting these parameters, we know the total number of wires. Before setting up all the tools, you can get an idea of the number of cables by totaling the number of connections.


Do you know the most significant advantage of wires? They not only transmit data but also contribute to the distribution of power. Each port will contain 15 watts when it comes to IEEE 802.3af. A similar pattern goes true for other Ethernet standards. Power overload can shut down your system. Therefore, Ethernet ports back up the whole system and let it work effectively.

Do you want to buy PoE injectors and other devices? Maybe you need tools for your Gigabit Ethernet and relevant technical systems. If so, HoweVision Professionals can provide you with all the options. We have the best industrial PoE switches, Gigabit, and Fast Ethernet technological equipment.

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Hi, I'm Mr. Hua, The funder of HoweVision technology, I'v been woking industrial communication equipment for 8 years now, and the purpose of this article is to share with you the knowledge related to industrial communication from a China supplier's perspective.

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