I can't remember the last time I reviewed a basic router. We've had anti-spam appliances, firewalls, multi-layer switches and all manner of other multi-purpose boxes, but it's reassuring to know that alongside all these clever gadgets there's a place for a box that just does routing.
The 3012 is an entry-level LAN-to-WAN router that's clearly designed to be used in a small or home office. It's a small grey box a little dinkier than a laptop PC, with an external power brick, and which as a result makes absolutely no noise (with an external PSU, you don't need a fan). The connections are all on the back - a pair of DB50 serial ports, a 100Mbit/sec Ethernet socket, and a pair of RJ45 serial ports, one for a direct-connect console, the other to connect to a modem for remote management and backup connectivity. Other products in the 3000 range offer different WAN connectivity such as E1, PRI and ISDN. The 3000-series are all low-end routers, all the ports are built-in so nothing's user-swappable.
The 5012, which is more of an enterprise box, has much in common with the 3012, not least that it has the same three console, auxiliary and Ethernet RJ45s. The 5012 is, however, much more expandable - the back panel contains two SIC (smart interface card) slots and one MIM (multifunctional interface module) slot into which you can shove extra cards, eg. multi-port serial, E1/PRI, Ethernet or ISDN MIM cards, single-port Ethernet, serial or E1/T1 SIC cards, or two-port ISDN SIC cards.
Because it's designed to sit in a comms rack rather than in a corner of an office, the 5012 has an internal PSU and associated noise-generating hardware, but this is not a problem for this type of unit. If you want bigger, scarier routers with lots more ports, by the way, 3Com also has its 6000 range, with similar capabilities but on a grander scale - more, bigger slots and thus support for more ports.
The 3012 and 5012 are both managed via terminal connections. Initially this means linking a PC to the console port, though once you've got it talking IP you can use Telnet over the LAN. If you want something with a pretty Web GUI, you're looking at the wrong devices - it's strictly command line territory unless you want to shell out for 3Com's management tools.
Because it's all textual, the command line interface takes a bit of getting used to. The main thing to get your head round is that you can switch between 'views', so to configure system-wide stuff such as routing tables you need to be in the system view, to configure an Ethernet adapter's IP address you need to be in the interface view, and so on.
The documentation is pretty poor for beginners. Apart from the basic configuration guide, the main lump of words is a reference volume which simply gives a section-by-section list of commands, with little concept of "here's the sequence you go through to achieve X". (There again, the 3000-series is a little too "Janet and John go networking" in places - do we really need a three-step instruction sequence on how to mount the unit on a workbench?).
Still, once you've twigged what's going on, it starts to become intuitive. There's a lot of stuff in there to configure though, so be prepared for a long session if you have complex requirements. Because they're real routers (not like those nasty routing switch things that only do IP) you get proper multiprotocol support (IP, IPX, X.25, Frame Relay and so on) as well as VPN (multiple flavours including the obvious IPSec), multicast routing, 802.1Q VLANs and an assortment of resilience protocols such as VRRP. There's also some built-in firewall capability - after all, you'd expect the router between your network and the rest of the world to handle some of the packet-dropping task, in order to relieve the load on your firewall.
It's reassuring that, in this age of multi-everything network devices that do everything bar feed the cat, a company still makes a decent range of proper routers. It's slightly disturbing that 3Com is still writing sub-standard manuals, and it's a little disappointing that you have to fight with a command line to configure these units. The redeeming feature to both of these issues is, however, that once your brain gets tuned to how the command hierarchy works, it really isn't as hard as it first seems.
Although basic WAN services tend to come with the router thrown in and looked after for you, if you have more complex requirements then you may well want to look after the routing aspect yourself. Because 3Com has a range of units, you can get a collection of small, medium and large routers that share a common configuration language and which you know will interoperate correctly.