Power over Ethernet (PoE)

Correct Answer: Use a PoE switch that supports 802.3at standard

The PoE switch supporting the standard IEEE 802.3af can provide power up to 15.4W and the cameras need 15W of power for each. This may cause issues as some power is lost through the cabling. Therefore, using the power over Ethernet switch that supports 802.3at standard (PoE+) is a better solution as it can supply up to 25.5W of power per port. The other answers are inappropriate because a non-PoE switch with power injectors and power splitters might add unnecessary complexity to the network, while replacing the cameras with lower power models might not fulfill the company's requirements.

Correct Answer: Insufficient PoE power

The most likely cause of the security cameras not turning on is 'Insufficient PoE power'. PoE, or Power over Ethernet, is a technology that allows network devices such as security cameras to receive both power and network connectivity using the same Ethernet cable. If there's insufficient PoE power, the cameras might not have enough power to switch on. As for the other options: 'Wrong network protocol' is incorrect because network protocols are related to how the data is transmitted and interpreted, not to power issues that could prevent a device from turning on. 'Malware' is not likely the correct answer in this case. While malware can cause a wide range of problems for network-connected devices, they typically would not prevent a device from powering on. Lastly, 'Outdated firmware' could potentially cause issues with camera functionality and performance, but it is unlikely to prevent the cameras from turning on altogether. Generally, firmware would have to be severely corrupted to prevent power-up, and such situations are rare compared to power supply problems.

Correct Answer: PoE switch

The best answer is 'PoE switch'. Power over Ethernet (PoE) is a technology that allows network cables to carry electrical power. For devices like VoIP phones that require both power and data connections, a PoE switch is the ideal choice as it combines a network connection and power supply in a single cable. 'Managed switch' and 'Unmanaged switch' do not necessarily provide the PoE feature, as their names simply reflect their level of management capability. The 'Non-PoE switch' obviously cannot provide power to devices, thus it is not suitable for connecting a VoIP phone that requires PoE.