It's hard to know where to categorise Apple's Time Capsule. It combines a 3 port gigabit router, USB file and print server, dual-band wireless access point and 1TB NAS appliance. For many home users, the Time Capsule will be the only device they'll need to manage their connectivity and shared data storage. If you're trying to manage costs, there's also a 500GB version.

At just under 20cm by 20cm and less than 4cm tall, the Time Capsule looks like no other router or NAS on the market. There's a single LED in the front corner (that can be turned off from the Airport Utility) that's green if all is well and amber if the Internet connection is down.

The Time Capsule is primarily designed for Mac users wanting to take advantage of Time Machine, OS X Leopard's fully automatic backup system. However, Windows users can access the hard disk within the Time Capsule just like any other NAS although they will need to install Apple's Bonjour software to do this.

The Time Capsule is set up like any other Apple network appliance. We installed the latest version of Apple's Airport Utility. The software detected the Time Capsule and ran us through an easy-to-use wizard. Our only criticism of the set up process is that it depends on the installation of a special application and can't be done from a web browser.

Accessing the 7200RPM SATA drive is very simple. For Mac users, the Time Capsule appears in the Finder. You can then open the disk and deposit files to it directly. While that's handy, the real killer feature of Time Capsule is that it just appears as a an available backup location within Mac OS X 10.5's Time Machine's settings -- the user doesn't have to stuff around with mounting network disks and so on. During the Time Capsule's initial setup, the user is asked to specify a password for router admin and disk access (two different passwords, or the same if the user prefers), so, despite the fact that the disk appears automatically in Time Machine, it's still a secure setup.

The first backup to the Time Capsule, from our MacBook Pro over 802.11n wireless, took 7.5 hours. This covered 56GB of data. Users with more data on their hard drive -- e.g. the 250GB on the latest MacBook Pros -- will need to plug their Mac directly into the Time Capsule using an Ethernet cable, otherwise, the backup will take several days (in fact, in APC testing, backing up 250GB over gigabit ethernet still took 9 hours.)

On the Windows side of things, after installing Bonjour, life was very simple. When our test system, a Toshiba Portege R500, booted up, we were prompted to connect to the Time Capsule. After accepting the connection, we launched Windows Explorer. The hard disk in the Time Capsule appeared as a mapped drive that we could copy files to it just like any attached storage.

Wireless connectivity supports 802.11, b, g and n and both the 2.4GHz and 5GHz frequencies. The 5GHz frequency support (also found in all the Macs that support draft 802.11n) is a big advantage over other manufacturers' wireless gear. Most manufacturers only support the 2.4GHz frequency, which is very crowded with microwaves, cordless phones and umpteen wireless access points in it. The 5GHz frequency is little used, and also has 23 non-overlapping radio channels, compared to 802.11g's three.

The downside, of course, is that if you run your Time Capsule locked to 5GHz 802.11n, only devices that support 5GHz 802.11n can connect to it (mostly recent model Macs!) One good compromise, though, is to run the Time Capsule as a 5GHz 802.11n wireless access point for newer Macs, and run your existing wireless modem/router as an 802.11g access point for older devices. The two won't interfere with each other.

In our testing we found that the Time Capsule had good wireless range. We maintained a connection at over 20 metres of distance through walls within a house. Given that there are no external antennae this is quite a feat.

The USB port offers great flexibility. We connected a USB hub and then piggy-backed a couple of USB hard drives and a printer. Our Mac could see all the devices as regular network devices. The same went with Windows although printer set-up requires using the Bonjour Printer Wizard.

Despite the ease of use that Apple's delivered with the Time Capsule there were some significant issues. With only one hard disk and no RAID or other redundancy, your data has only limited protection -- and this is a legitimate concern, considering the Time Capsule appears to run quite hot. Also, if the drive fails you'll lose your router as well as NAS. While the integration reduces office clutter, it is a double edged sword as it introduces a single point of failure. Apple is evidently keen to keep people in the upgrade cycle in the future ... the Time Capsule is a sealed unit so you won't be able to upgrade it if larger hard disks become available.

The Time Capsule differentiates itself from other routers on the market by only having three LAN ports. Why Apple chose to eschew the established industry expectation of four ports is anyone's guess (though it does have a fourth port -- but it's used for the uplink to your broadband modem.)

Also, the lack of traffic prioritisation and filtering might make business users think twice. If you're running VoIP and suffer some sort of connection constraint, there's no way to give VoIP priority so that call quality isn't compromised -- a rather surprising oversight for what is otherwise a very capable router.

Many Mac users boast that their systems "just work" - the Time Capsule, in our testing delivered that experience. However, buyers need to be aware that there are some limitations.