Networking
PoE
Also called: Power over Ethernet, 802.3af, 802.3at, 802.3bt
Delivery of DC power and data over the same Ethernet cable, so cameras, access points, phones, and displays need no local outlet.
The three tiers matter for design: 802.3af (PoE) supplies about 15 W, 802.3at (PoE+) about 30 W, and 802.3bt (PoE++) up to roughly 90 W. Cameras with heaters, PTZ units, and touch panels sit in the upper tiers, and a switch that supports the standard on paper may not support it on every port at once.
That last point causes most PoE failures. A 48-port switch often has a total power budget well under 48 × 30 W, so a fully loaded camera floor browns out devices intermittently. We budget PoE watts per switch the same way we budget amplifier watts, and put PoE switches on UPS since they are now the power source for the security system.
Support305 designs and installs these systems across South Florida.
Network cablingRelated terms
- VLAN
- A logical network segment on shared physical switching, used to isolate device groups — cameras, AV, guest Wi-Fi, corporate data — from each other.
- IP Camera
- A network camera that encodes video onboard and streams it over Ethernet, typically powered by PoE and recorded by an NVR or video management software.
- UPS
- A battery-backed power source that keeps equipment running through outages and, just as importantly, filters the sags and surges that shorten hardware life.
- Cat6 vs Cat6A
- Two copper cabling grades: Cat6 supports 10 Gbps to about 55 m, while Cat6A supports 10 Gbps to the full 100 m and resists alien crosstalk in dense bundles.
More Networking terms
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