I keep getting various questions about CRBT ( Caller Ringback Tone) and IVRS, their relation. My answer is CRBT is essentially an application that uses IVRS and smart call routing.
This CRBT is marketed by different names by different Mobile Operators! The list might be interesting to publish! Most commonly used in India are, Hello Tunes, Caller Tunes, Dialer Tune etc.
What is CRBT?
When person A calls person B, if person B is available, then person A hears a ringback tone! Now CRBT replaces that ringback tone with a selectable music. So, now, a person A dials person B, person A gets to hear a music, person B has selected as his CRBT Tone. Person B has also option for playing a particular music according to caller ID. For example I can set music “Welcome to the Hotel California” when my friend calls me while I can record a message, “Testing IVR Application” which will be played when ever my boss calls me.
CRBT can be implemented various ways! The easiest way is using SS7 call routing and IVRS. ( This is not a technical guide to start a CRBT Service, but just logical explanation. For technical solution, contact me separately or any other CRBT Solution provider.)
1. Switch receives a call from Subscriber A to Subscriber B.
2. Switch routes the call to IN ( Intelligent Network) System. IN System will check if subscriber B is available, if yes, it checks if Subscriber B is a CRBT Subscriber. If no, it sends back to the call to connect the call normally. If yes, it asks switch to dial out Subscriber B, while it transfers the call to CRBT Server, which is nothing but IVRS Server. As soon as IVR receives the call, it plays back the pre-programmed music as per caller id or the Subscriber B.
3. IN System keeps monitoring the switch dialing out to Subscriber B. As soon as Subscriber B receives the call, or disconnects it, IN system disconnects from CRBT Server, asks switch to connect subscriber A and Subscriber B.
Quite simple, eh ? Not actually! A CRBT server needs quite a bit hardware, many big Teleocm jargon, like MTP, ISUP, SCP, SSP, SS7 Link, MAP apart from big database of music, along with copyrights!
If you are jumping the CRBT business after seeing those advertisement and news on news papers, you may have to do a rethinking!