[asterisk-dev] How to generate ast_frame with RINGBACK tone in * ?

[Rus V. Brushkoff]

 	Hi,

  I have dumb device that do not has RINGBACK tone generator inside, so 
when this device is calling somebody it simply opens the audio channel. I 
can send to this channel RINGBACK tone in channel_write() function, but 
how this tone can be generated in pure Asterisk (without any DAHDI 
helpers) ?

TIA

 		Rus