I can highly recommend the Siemens Gigaset S685 IP Eco Dect Phone as it is something I use in my own home office. This phone allows me to make and receive landline calls as well as VOIP or SIP calls. It can support up to 6 VOIP or Sip Accounts. I have teamed mine up with two Sipgate telephone numbers.

The phone supports HSDP (High Definition Sound Performance), so the call quality is superb when making voip calls. You can assign different lines to different handsets, and set the hardware voicemail to act as the default mailbox, for all lines using the phone. The phone can also sync, via bluetooth, with Outlook or any other PIM application. In my opinion, the sync software still needs some refining but it is adequate and not the worst I have used.

If you type and talk a lot, then you will be pleased to know that you can pair a bluetooth headset with the phone too.

Skype users will be disappointed to know that it doesn’t support Skype but this is because Skype doesn’t use the SIP protocol. Who knows, in the future either Skype will make the sip protocol available to consumers, or Siemens will upgrade their firmware and allow for Skype calls to be made using this device. Until that time comes, Skype users like myself, will have to make do with using a proprietary Skype DECT phone, PC software and headset, or mobile phone application.

So to conclude, this is an essential product for any serious home office. Get one as soon as you can possibly afford it!