Now a part of Microsemi, Power over Ethernet (PoE) pioneer Powerdsine has introduced a new range of mid-span hubs able to offer a lot more electricity over the Lan than existing products.
Built to conform to the yet-to-be-ratified 802.3at (PoE Plus) standard from the IEEE, the new hubs also come with Gigabit Ethernet ports, bundled management software and a lifetime warranty.
PoE is popular with businesses of all sizes as it allows devices such as wireless access points, Voice over IP (VoIP) handsets and network cameras to draw their power over the same cables that are used to connect them to the Lan.
It does away with the need for local AC adapters and enables devices to be positioned in places where power doesn’t reach. It also facilitates central management of power distribution, for example, by shutting down power on specific ports out of hours.
Unfortunately the current standard (IEEE 802.3af) can only deliver around 13-15W per port, limiting what can be powered. The latest 802.11n Wifi access points, for example, need more than that to operate, as do cameras with pan/tilt/zoom (PTZ) motors.
The upcoming 802.at specification addresses this by allowing 30W or more to be delivered using spare cable pairs in the network wiring, enough to drive both these devices and others such as thin clients and point of sale terminals.
Microsemi is the first to deliver a pre-standard product, with three hubs in the Powerdsine 7000G family. We tested the top-of-the-range 7024G, which has 24 Gigabit ports, while for smaller deployments there’s a 12-port 7012G (£402 ex Vat) and six-port 7006G (£352 ex Vat).
The same very substantial 1U rackmount chassis is used in each case with all the ports at the front together with a separate connector for attachment of a local console and a serial port for uninterruptible power supply (UPS) control.
There’s no real switching intelligence inside the 7000G because it’s a mid-span hub. It simply injects power into network cables with two connectors for each port, one connecting to the host switch, the other delivering the data and power mixed. A single integrated power supply delivers the electricity to the unit, which can be UPS protected if required.
Installation is very straightforward. We simply unplugged our test devices from an existing switch and plugged their cables into the powered ports on the 7000G instead. We then used short patch leads to connect the matching connector for each powered port back to the original switch. The hardest part was getting hold of suitable patch leads as they are not included.
Remote management is built in with simple web-based access to the Powerview
Pro software,
as well as support for Telnet and SNMP consoles.
Backwards 802.3af compatibility means that existing devices are safe to use with the 7000G hubs and we had no problems with any we tried.
Pre-standard 802.3at devices aren’t really available so we couldn’t test any, but you can get high-power splitters (Powerdsine 701, from £35 ex Vat) to work with a range of devices including those that can only accept voltages below those defined by the standards (44V with 802.3af and 50V with 802.3at).
As the name implies, these split the mixed data/power lines into separate Lan and DC ports, at the same time stepping down to 24, 18 or 12V.
All Network Tools Tags: Power-over-ethernet, Powerdsine, Poe


