With the Gigaset C470IP, Siemens combines Voice over IP (VoIP) and PSTN functionality in a dual-mode phone with a bevy of features that should suit the typical home user. Support for six different handsets and three simultaneous calls over the handsets also make it a viable option for a small office or busy house.
The C470IP isn't the prettiest device, but it's the functionality that counts. The device supports six different SIP accounts as well as a PSTN fallback line, effectively allowing users to mix and match seven different telephone operators in order to get the cheapest local and international calls. The carriers aren't tied to specific handsets either — users simply add the designated carrier number to the end of their dialled number, on any of the six handsets.
The C470IP handset fits snugly into a minimal charging dock. Apart from basic speaker phone and room monitor capabilities, the handset ambitiously offers instant messaging, POP3 e-mail and fixed line SMS capability.
Although the presence of these features doesn't hurt the device, it doesn't really benefit it either. The problem largely lies in the handset's LCD screen, which displays only 4096 colours at a 128x128 pixel resolution. The C470IP's fixed line SMS function is similar enough to traditional mobiles to be comfortable to use. However, text-intensive functions such as e-mail and instant messaging are ultimately let down by the handset's poor screen and numeric keypad.
A base station provides the phone's connectivity. Smaller than those found in most other units, the C470IP's base station is adorned by a single back-lit button that lets you page the handset. Cable management is provided on the back of the base, but only for the power adaptor and PSTN RJ-12 line. The Ethernet port, on the other hand, is on the side of the station, making for a rather unsightly look.
A single VoIP carrier can be configured using the handset, while the device's embedded Web server provides access to large array of other options. Unlike the convoluted Web interface of Linksys' IP Phone SPA962, the C470IP's interface is simple, well laid out, and extremely easy to use. Users can access and configure VoIP carriers, POP3 mail accounts and administer handsets. Instant messaging is also configurable, but the setup process for this is rather convoluted. Users must first configure their preferred instant messaging settings from a PC using the Jabber protocol, which provides interoperability with other IM services.
Call clarity is where the C470IP shines most. Using the same Freshtel account we tested with the Linksys IP Phone SPA962, the results were quite surprising. The SPA962's handset produced a tinny and cold voice — something we attributed to the VoIP connection — but the C470IP produced a voice with a warm timbre that made for a pleasant conversation. The respondent claimed the same result, saying our voice was indistinguishable from a traditional landline.