12voip offer Free pc to phone to China:

China (Landline) 0.000 (Euro cent)
China (Mobile) 0.000 (Euro cent)

You just need to buy a voucher 10 Euro and than you can make calls to china 90 days at no costs (Important* you can call up to 300 minutes per week to a FREE destination) after 90 days the rate will change to:

China (Landline) 0.01 (Euro cent)
China (Mobile) 0.01 (Euro cent)

12voip, what is it?

12voip is a free program that uses the latest technology to bring free and high-quality voice communications to people all over the world. When you use the free 12voip software, you can call regular phones in various popular destinations for free* or call at an incredible low rate to any other phone on the planet. You can also call all your online friends (peer-to-peer calls) as long as you like, for free. Just click here to download 12voip; the download should take only a few moments depending on your connection speed.

12voip provides you with the cheapest international calling rates available!

Another incredible feature is that you can talk for FREE with other Actionvoip users. (pc-to-pc).

Download 12voip free software and start saving on your international calls!

Just follow these three easy steps to start saving on your calls immediately :

1. Download the client
2. Buy credits
3. Start calling!

You can use 12voip at SIP device, this software configuration that you need:

General
SIP port : 5060
Registrar : sip.12voip.com
Proxy server : sip.12voip.com
Outbound proxy server : leave empty
Account name : your 12Voip username
Password : your 12Voip password
Display name/number : your 12Voip username or voipnumber
Stunserver (option) : stun.12voip.com

Below are some examples of the software configuration of various popular SIP devices. Please also consult the manual that came with your SIP device

Codecs
G.711 (64 kbps)
G.726 (32 kbps)
G.729 (8 kbps)
G.723 (5.3 & 6.3 kbps)
GSMFR (13.2 kbps)

(Source:www.12voip.com)