[asterisk-biz] GSM cellular network (Global System Mobile)

[Trevor G. Hammonds]

From: Michael Welter
> 
> Does anyone know how CallerID is passed to a GSM cell phone?  Is the
> audio channel used?  Or the signalling layer?

Caller ID display is handled at the signalling level on GSM networks.  

> Even though the phone's codec is optimized for speech, is it possible
> to use FSK (frequency shift keying) through the codec?

Cannot help you here.

		Sincerely,
		Trevor Hammonds