24-port PoE Ethernet switches

HP went a little over the top with the product they sent us, submitting one of their newly launched Gigabit switches. That, of course, makes the ProCurve 3500yl a lot more expensive than the others, which only use Gigabit on their uplinks. However, we've included it, both for completeness and because it's the Power over Ethernet support we're most interested in.

Despite the price, the 3500yl doesn't look that special, housed in the now standard 1U rack-mount case with all 24 of its UTP connectors at the front. Unlike the others these are all Gigabit Ethernet ports and there are no separate uplinks. Instead, four of the ports are dual-personality with a bank of matching slots alongside to take fibre optic adaptors. There's also a slot at the back for an expansion module that lets you add a further set of four, this time 10Gigabit interfaces which would typically be used to connect the switch to a high-speed backbone LAN.

Any of the ports can also be used to link switches, to build a stack of up to 16 altogether, and all managed via a single IP. However, power is only supplied to the 24 ports at the front and is disabled on the dual-personality ports if a corresponding fibre optic adapter is inserted.

In terms of power there's both a built-in AC supply and sockets for an external backup unit which, unfortunately, hadn't been released when we reviewed the product. With or without it, however, the switch has a massive 398W on tap enabling it to deliver the maximum power specified by the 802.3af standard (15.4W) to all 24 ports simultaneously - the default setting.

Management choices include a local console port, telnet, a Web-based interface and SNMP with a copy of HP's preferred management console (ProCurve Manager) included with the switch.

We tested using the Web interface which proved very responsive. A graphical status display shows which ports have power applied, but you can't configure the PoE setting from here. Instead you have to go to a separate window and configure the ports that way. Fortunately this is quite straightforward and boasts the usual options for enabling/disabling PoE to each port, prioritising power delivery and setting power ceilings.

Given the high price it came as no surprise to find support for VLAN network segmentation, Layer 3 routing and Quality of Service (QoS) features, all of which can be configured via any of the supported interfaces. Neither were we surprised to find the 3500yl capable of handling anything we connected to it, delivering all the power needed to handle our PowerDsine tester, test access points and IP phones. According to HP it can also cope with pre-standard PoE devices, although you need to check its compatibility list before trying this out.

Overall, then, a very impressive switch with excellent Power over Ethernet capabilities and top notch management. But - and it's a very big but - it's a lot more expensive than the others and with powered devices having Gigabit interfaces the extra bandwidth is a questionable benefit.

Instead we suggest you look at the ProCurve 2626-PWR - a more modest 24-port 10/100Mb/sec switch costing half the price but still with 360W of PoE on tap.


Impressive but you do have to pay for it and cheaper products can be just as effective

Type: Layer 3 Ethernet switch Gigabit ports: 24 - 4 shared adapter slots for fibre connectivity + optional 10GbE uplinks Switching capacity: 101Gb/sec MAC addresses: 10000 VLANs: 256 PoE budget: 398W Redundant power: Yes