Internet telephony is most useful when it’s easy to use, and Siemens’ S450IP sets out to make standards-based SIP telephony as easy as an ordinary phone.

It’s a Dect handset that also plugs into your Lan, so you can make calls using the fixed line or a SIP provider.

Setting up SIP accounts can be done via a simple wizard. You choose one service as the default and calls are automatically routed that way. Hold the green phone key longer and calls go via the other route; emergency calls can be routed automatically to the fixed line. It’s easy, and works very well.

You’ll be told if a call is via the internet or landline on a large, colourful screen. This screen also lets you browse the 150-number directory; individual entries can be marked as VIP and given their own ring tones. You can import contact details, but it's a fiddly process.

There’s support for SMS with predictive text, though it’s not as easy to use as on a mobile with proper T9 texting. On top of that, there’s also a Jabber client built in, so the phone can receive instant messages. We had no problem chatting to Google Talk users, but you’ll need to use a PC to set up your buddy list. And as if that’s not enough, you can even enter details of a Pop3 account and you’ll be notified of new messages – though you can’t read them on the phone.

Homes with several users will appreciate the ability to add extra handsets. Each one can be set up to use a specific SIP account for outgoing calls, and to ring only for particular accounts too. Only two simultaneous calls are possible, but it’s still a great way to provide a complete phone system.

Aside from some niggles with the predictive text, which are common to many cordless handsets, this really is a first class Dect system.