[Asterisk-video] hot to know a mobile device supports video call when trying to do outbound 3g video call

[Konstantinos Liadakis]

Hello list,

Is there any way to know if device supports video call, or if device 
supports video calls but is not within 3g coverage when trying to make 
outbound video call and call fails.

During my tests i have seen that sometimes calls go through to devices 
without video capability. In this case i found a message in mobiles 
voicemails with just a buzzing sound.

How can we avoid sending 3g video calls to non capable devices? Could 
someone post a dialplan that could do that?

thank you in advance

dinos