- port of embarkation
- port of entry
poe - Computer Definition
The IEEE 802.3af (June 2003) standard that defines how power is delivered over twisted pair to devices also using 10Base-T, 100Base-T, and 1000Base-T technologies. PoE provides electrical over two Cat 5e or Cat 6 wire pairs separate from those used for data transmission, except in the case of 1000Base-T. PoE not only provides an alternative to expensive electrical cabling in hard-toreach places, but also alleviates concerns about power outages if an uninterruptible power supply (UPS) is available. PoE specifies that the power sourcing equipment (PSE), or power injectors, provide output of 48V DC power over the cable plant to terminal units that provide 12V DC output to PoE-compliant devices known as powered devices (PDs). The 802.3af standard also specifies four different power draw levels of up to 3.84W, 6.49W, 12.95W, and 15.4W for attached devices.The PSE automatically senses the power requirements of the PDs, including IP phones typically drawing 3-5W, wireless access points (APs) typically drawing 6-10W, and security cameras typically drawing 9-12W. PoE typically involves power supplied directly from an Ethernet switch to a client device, although there are provisions for midspan power injectors. See also 10Base-T, 100Base-T, 1000Base-T, AP, Cat 5e, Cat 6, DC, Ethernet, LAN switch, UPS, and volt.
(Power Over Ethernet) Distributing power over a CAT5 Ethernet cable to a target device that is not plugged into an AC wall outlet. PoE enables remote network devices such as ceiling-mounted access points and surveillance cameras to be installed far away from AC sources. It also eliminates the bulky AC adapter for each device (see wall wart). In addition, PoE can be used as an electrical source for the most efficient LED lighting (see PoE lighting). PoE sends electrical power over unused wires in eight-wire cables and over signal wires in four-wire cables. PoE networks are created with a PoE-based Ethernet switch, but PoE can also be added to a non-PoE switch. In addition, regular Ethernet devices can be used in a PoE network (see illustrations below). See Ethernet, IP phone, PoC and network camera. IEEE Maximum Type Standard DC Watts PoE 802.3af-2003 15.4 PoE+ 802.3at-2009 25.5 Linear Technology Proprietary LTPoE++ Four power levels 38.7, 52.7 70.0, 90.0