Netgear launches a switch that can't even power itself.
Over the past year I've seen a few pieces of equipment that support the often misunderstood PoE or Power Over Ethernet standard. The concept behind this technology is that the eight wires that make up Ethernet are enough to carry both data and power if used intelligently. It works well with devices like security cameras, as it's much easier to run a network cable than deliver mains power to many install locations.
The GS105PE is a switch that was made by Netgear specifically for supporting PoE situations and has five ports that between them support gigabit Ethernet and a couple of PoE standards. Those being; 802.3at Type 1 (802.3af) and 802.3at Type 2. What really confused about this device initally, though, is that it has no normal means of powering itself; instead, it uses PoE. That reduces the useable ports to four, though one port would always be used as a link back to a router or another switch anyway.
This decison does, however, pose a couple of critical questions about how this device might be used and the practicalities of some features it has. For starters, 802.3af has a cap of 25 watts input, and it translates that into a 20 watt budget for redistribution. It’s only half that if you use 802.3at. That means the most it can deliver is 10 watts downstream to the two PoE PSA ports it has. That's a bit on the light side and, by definition, you couldn't chain these or support more than two devices. The GS105PE is also designed to give power priority to one of the PSA ports and will chop power to the other if the first one demands more than 50% of what is available.
The other curiosity is that they made it gigabit and gave it a 2GBit backbone, yet I'd always assumed that using some of the lines in Ethernet negated the use of anything other than 100Mbit links. This proved to be an education, as I discovered that PoE can be used on gigabit Ethernet links on an 802.3af link using 'phantom power' mode. Using this method, data and power can travel on exactly the same pieces of wire at the same time, amazingly.
Some of my technical explanation hints at how specialist a device this is, and as such it is probably only of interest to IT people who manage large locations and want to deploy wi-fi or security devices to remote parts of it as easily as possible.
The price seems very reasonable, but when you factor in that you need another PoE switch to power this one, costs could spiral rapidly.
What would put me off buying one is that it only delivers a maximum of two powered ports and the wattage available is limited. If you've got a very specific job and use PoE already then it might be the right choice, but it's a very niche solution. Mark Pickavance
A PoE switch that uses PoE power itself. A specialist device for niche applications.
Key Features
• 5x 10/100/1000 gigabit ports deliver dedicated, non-blocking bandwidth per port.
• 2x 802.11af Power over Ethernet pass-through ports, maximum budget 20W.
• Single PD port, this switch is powered by another PoE enabled device (No PSU supplied).
• QoS and VLAN support for traffic segmentation.
• Auto denial-of-service (DoS) prevention.
• IGMP snooping v1, v2 and v3 support for multicast optimisation.
• Jumbo frame support.