I've been trying out HP's iPaq 514 Voice Messenger phone, which turns out to be a very nice lightweight handset despite having built-in Wi-Fi and Bluetooth wireless interfaces.

This Windows Mobile 6 device also comes with a built-in SIP client for IP telephony, which is designed to pair up with a SIP server or IP PBX when a worker is in their office and in range of the corporate Wi-Fi network. The problem is, how to go about testing this without access to such infrastructure?

Fortunately, it turns out that there are online SIP service providers that allow you to access IP telephony over a broadband internet connection. Many of these, such as the one I chose to try out – Freespeech.co.uk – are free to sign up for, and offer free calls to other VoIP numbers.

Armed with an 0844 number and my registration details from Freespeech, I set about configuring the iPaq 514 to connect. However, it turns out that the SIP client cannot be configured from the handset itself. Users instead have to link the phone to a Windows PC and use the HP iPaq Setup Assistant that comes on a CD-ROM with the phone.

This tool turns out to be very handy and lets you configure almost all aspects of the handset, including Wi-Fi access point settings, email accounts, speed dial numbers, and even populate the browser Favourites list.

With all necessary configuration information entered, I turned on Wi-Fi and connected the phone to my wireless router at home. The VoIP client then looked for the SIP server and connected, showing the status message "freespeech.co.uk selected". The "selected" part means that any calls made will now go via the internet instead of the cellular network.

I made a quick call using the phone to a colleague that had also signed up on the same service, and found the call quality excellent, if a little on the quiet side.

Overall, I was surprised at how easy it was to get voice-over-Wi-Fi working on this handset. That said, the settings Freepeech emailed to me did not exactly match those in the iPaq 514 configuration screen, and I had to make an educated guess to bridge the gap between the two.

The only drawback to this setup is that I now have a separate phone number for calls made over VoIP that differs from my landline and the mobile number of the iPaq.

This will probably not be a problem in a business environment, as the SIP service will link to the corporate infrastructure and probably tie in with the user's desk phone. For home users, the Unlicensed Mobile Access (UMA) VoIP protocol, which features in RIM's new BlackBerry 8820, instead links the handset with the mobile carrier's infrastructure.

A full review of HP's iPaq 514 Voice Messenger will appear in a future issue of IT Week.

26 Jul 2007