June 15, 2023
PoE power refers to transfer of power when transmitting data to network devices without changing original network architecture. The carrier is network cable.
There are two ways to deploy PoE, one is terminal access method and other is intermediate access method. When properly deployed, it is safe, reliable, and cost effective.
In order to solve your PoE power problem, it is very important to understand these 5 points.
1. Provide sufficient power to equipment
The PoE power module used in medium access method (also take 24 ports as an example) should not be lower than 370W, and output power of 24-port PoE switch should be greater than 370W. Much depends on switch Power consumed during data exchange.
Normally, a non-PoE switch can be used to measure power consumed by switch itself, plus 15.4W per port, you can get minimum output power required by PoE switch.
2. Use an uninterruptible power supply such as a UPS
Some PoE-powered devices are often mission-critical devices, such as Internet phones. After power is turned off, voice will be completely muted and call will not be possible.
Whether it's a traditional softphone or an IP phone, it's important that it's seamless. Therefore, when designing a network, it is necessary to isolate such key equipment that cannot stop power supply or data transmission, and use uninterruptible power equipment such as a UPS for backup power to ensure uninterrupted power and data transmission.
3. Use switches that comply with PoE power standards
When deploying PoE, you need to make sure that power supply side and power receive side must be compatible with each other. Before using equipment, it is recommended that you carefully read instruction manual and its technical parameters. If this is not possible, you should contact manufacturer's technical support service to make sure that power supply and power receiving equipment you use is compatible. together.
4. Cable characteristics cannot be ignored
When choosing, try to use higher grade cables. The higher cable class, lower power loss and higher performance.
Only four nodes are allowed between switch or hub and NIC. If passthrough method is adopted and a PoE power module is used for power, then module itself is also considered a node.
So distance from switch/hub to network card is 100 meters, not 100 meters from PoE power module to powered device, since length is not determined by power supply, but by data transmission.
5. Use a More Cost-Effective PoE Deployment Method
The terminal access method usually uses a PoE switch as power supply device. This method is recommended for a new network because topology is simple and it's not easy to make mistakes when connecting.
If you recently purchased or upgraded a switch and now want to deploy PoE equipment and find that switch you just purchased does not support PoE, we recommend that you use passthrough method.
Middle access method: connect a PoE power module between source switch and a powered device that is also 802.3af compliant, and problem can be completely solved with a small increase in cost.
In recent years, pace of development of PoE power supply technology has become stronger and stronger. With a number of advantages such as simplified installation and deployment of electrical equipment, energy saving and security, PoE power supply has become a new favorite in scenarios such as wireless coverage, security monitoring and smart grids.
As a security professional, we also need to study and update our technologies so that they don't get destroyed by time.