A network administrator has deployed PoE to power VoIP phones across an office, but several of the phones are not powering up despite being compatible with the technology. The switch is PoE-enabled, and cables are all Cat 6. The administrator suspects that the issue may be related to a power standard mismatch. What is the most likely cause of the problem?
There is a firmware incompatibility between the VoIP phones and the PoE switch.
The VoIP phones and the switch are operating on incompatible PoE standards (e.g., 802.3af vs. 802.3at)
VoIP phones are set to a static IP causing conflicts in power allocation.
The Ethernet cables are damaged, causing insufficient power delivery.
The correct answer is that the switch and VoIP phones are using different PoE standards (802.3af versus 802.3at). The 802.3af standard delivers up to 15.4W of DC power, while the 802.3at (also known as PoE+) can provide up to 25.5W. Devices requiring more power than what 802.3af can deliver will not operate correctly if they are not compatible with or do not receive 802.3at power. In real-world networking, it is crucial to ensure that both power sourcing equipment (like switches) and powered devices (like VoIP phones) adhere to compatible PoE standards to prevent operational issues.
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