Avaya switch supplies power to IP phones

Avaya Inc. last month announced inline power capabilities for its Cajun stackable switch, allowing it to power IP phones through their network cables.

The new technology, based on the 802.3af standard for power over Ethernet, could eliminate the need to plug IP phones into a power outlet at an end user’s desk. Supplying power to IP handsets from a switch could also keep an enterprise IP phone network up during power outages, provided that the network switches and IP PBXs are attached to uninterruptable power supplies.

The 802.3af technology, provided by power-over-Ethernet component maker PowerDsine, is used within Avaya’s new Cajun P333T-PWR stackable switch, based on Avaya’s 24-port Cajun P330 switch. Avaya also announced that power-over-LAN technology will be added to its Avaya 4600 line of IP phones.

The PowerDsine technology allows power to be delivered to 802.3af-compatible end devices through the unused pairs of wires in a Category 5 network cable. (Cat 5 cable uses four pairs of wires, only two of which are active for transmitting data). The technology can also be used with legacy Category 3 wiring, the company said. The PowerDsine technology allows a switch to sense if an attached device is also 802.3af-compatible, ensuring that power isn’t sent to the network card on a PC, server or printer, which could damage the device.

Although Avaya is billing the 802.3af technology as a complement to its ECLIPS voice-over-IP products, the technology could also be used to power other small IP devices built to the 803.3af standard, such as wireless LAN access points.

Cisco was one of the first to introduce a technology for running power to IP phones over Cat 5 network cable, but its method is proprietary. Enterasys also includes a proprietary power-over-LAN technology in some of its switches for powering its line of wireless LAN access points.

The Cajun P333T-PWR will be available in October for US$4,300.

Avaya is on the Web at www.avaya.com.