The D-Link DPH-540 is a wireless Session Initiation Protocol (SIP) based VoIP Telephone, offering users the freedom of wireless connectivity and the benefits of VoIP. The DPH-540 uses 802.11g Wi-Fi technology to connect to a wireless network and doesn't require a PC to operate, so calls can be made wherever a wireless Internet connection is present.
As the DPH-540 is based on SIP, it won't work with other voice applications, such as Skype. To use the phone, users will need an account with a VoIP service provider, such as MyNetFone, for example. Setting up the phone requires access to a wireless Internet connection so that the VoIP account details can be entered and registered. The DPH-540 then connects to the VoIP service provider to allow users to make calls.
The DPH-540's design is a step forward for VoIP phones. It looks much like a regular mobile phone, and its clamshell form factor is the first of its kind that we've seen. The DPH-540 measures 113mm x 48.7mm x 25mm and weighs 115g, so it's one of the smaller VoIP phones on the market. It's finished in a rather subtle black and silver plastic and although we wouldn't describe it as attractive, the design certainly isn't bad.
The DPH-540 has an internal LCD display, but it's not as bright and clear as most mobile phone displays. The interface's colour scheme also makes it difficult to see some menu items. Indeed, white text on a light coloured background isn't the best combination for a hassle-free user experience. Despite this issue, the main screen can be read fairly well and shows battery life, wireless reception quality, the currently connected network, the time and date, as well as caller ID.
The DPH-540 has plenty of call features, including last number redial, mute, and hold. D-Link also uses echo cancellation technology, which worked quite well during our test calls. Call quality was good on both ends, with no major complaints from our call recipients. The phone is also fairly easy to use, as the buttons are well positioned and easy to press, and setting up a connection to a wireless network isn't overly difficult. However, when you set up wireless access points in the phone and save them, you'll have to go back to enable them. These few extra steps detract a little from the overall user-friendliness of the phone.
One complaint about connections is the fact that users have to configure them again each time they hit a new wireless hotspot. The DPH-540 doesn't automatically connect to available networks, so for travellers, this may become an issue. Users aren't able to synchronise contacts from their PC to the DPH-540's phonebook either.
One cool extra feature of the DPH-540 is email. A section in the phone's menu allows users to enter settings for POP3 and SMTP email accounts. We used a standard Yahoo! Mail account to test this feature and it worked quite well. Although this is never going to replace a BlackBerry, many users probably won't use this for any serious emailing, but for travellers, it's a nice feature to have handy. Unfortunately, the DPH-540 doesn't offer support for SSL or IMAP email accounts.