[Asterisk-video] Make 3G calls with a mobile phone directly connected to Asterisk

[David Florella]

Hi, 
 
I want to know if it is possible to connect a 3G mobile phone directly to
Asterisk instead of an ISDN line to make calls. 

For example, Bob makes a visio call whith Alice on her mobile phone : 
Bob sip client ==> Asterisk ==> 3G mobile phone directly connected whith
Asterisk ==> proxy server ==> Cisco Gateway ==> ISDN line
 
If it is not possible, I would connect my Asterisk to a proxy server to
receive the 3G calls. Is this work?

Thanks.