3Com Switch 4500G PWR 24-Port review
The latest switching products from 3Com have a keen eye on VoIP application. The new 4500G PWR sports features aimed at automating the addition of IP phones and prioritising their traffic. The switch also provides basic routing capabilities, supports virtual stacking, has a good range of security measures and all 24 Gigabit Ethernet ports can provide power to 802.3af-compliant devices. In terms ofcompetition, the 4500G has a lot in common with HP’s ProCurve Switch 3500yl-24G-PWR.
The 4500G also has four dual-personality ports that accept the full range of Fibre Gigabit transceivers. There are a number of options for 10 Gigabit Ethernet too, with the switch providing a couple of expansion slots. For short-distance InfiniBand cabling up to 3m, youcan go for the dual-port CX-4 module, which is aimed at connecting servers with high-bandwidth requirements or aggregating Gigabit links with high-speed switch-to-switch connections. For fibre backbones, 3Com offers a dual-port XFP module that accepts industry-standard 10GbE transceivers.
Installation is smooth, as you start with a serial port connection to the switch’s CLI and assign a static IP address to the default VLAN. You can then move over to the well-designed webinterface but, unlike HP, some features will require a trip back to the CLI. Fortunately, PoE is enabled on all ports by default, and you can set the maximum power a device is allowed to draw in milliWatts, assign power priorities and enter a power threshold that will cause an SNMP Trap to be issued ifexceeded. We successfully tested PoE capabilities with an Axis 221 network camera, but found the web interface doesn’t provide any information for powered devices – this can only be shown from the CLI.
Virtual stacking options are superior to those offered by HP, as up to 32 switches can be managed using a single IP address, and the cluster can comprise 4200G, 4500G, 5500 and 5500G models. However, it’s back to the CLI for this, as configuration isn’t possible from the web interface. The VoIP functions are accessible from the latter, although our settings weren’t always accepted and the advisory messages hadn’t been translated well. In the end, we went back to the CLI, where we started by creating avoice VLAN and adding selected ports to it. The switch can identify IP phones from their OUI (organisationally unique identifier), which is the first 24 bits of their MAC address. OUI lists for 3Com, Cisco and Siemens are provided, but it’s easy to add extra entries. When an OUI matching your list is spotted, the packets from this device are transmitted over the voice VLAN. It will also apply predefined rules from an ACL (access control list) andcan be set to block all other traffic from using this VLAN.
The 4500G PWR offers an extensive range of features and we liked the VoIP functions. However, HP’s 4500yl-24G costs less and delivers superior switch-management facilities.