PoE switches provide a stable and reliable network experience through wired connections, avoiding the interference issues of wireless signals. They use dedicated pairs of wires to separately transmit power and data, ensuring that network performance is not affected by the power. Power over Ethernet (PoE) switches are essential in many network setups, providing data and power over a single cable. However, the power supply stability of PoE switches directly affects the reliability. We have a SIP PoE phone system and we seem to be starting to have more complaints than usual with some phones malfunctioning. Here, we will list some common factors in this article. Therefore, everyone is concerned about whether PoE switches will affect speed.