Happy users of Apple IPhone will make it to call through VoIP netwok and it will take some 3-5 minutes to complete. I will describe this process for those, who have jailbroken iPhone.
First of all install from Cydia or from Icy the program called Siphone.
In menu Setting you've got an item called Siphone.
Follow the menu:
Settings -> Siphone ->
1. Enter your user name and password, which you've got after registration. For example you can get one in UcallWeconn.
2. Enter a server name: conus.ucallweconn.net
Go to extended settings and edit the following:
1. Registration timeout 3600
2. Proxy server: conus.ucallweconn.net
3. NAT support: yes (if you need)
4. Do not enter user name and contact
Go back to Settings:
1. Echo cancelling: On
2. Voice Auto Detection: Off
3. Codec: alaw
And finally edit the network settings:
1. Siphone over EDGE/3G: make it On if you want to use your VoIP client over your mobile operator. Attention! If you want to use Siphone through Wi-Fi, Siphone over EDGE/3G setting should be Off!
2. Port: 5060
3. STUN server and STUN domain leave blank
Press Home button and launch from Springboard Siphone. If you've done everything correct, then you will see Connected on your screen. From now you can place calls throug your GSM operator or UcallWeconn or any other SIP connectivity supplier.