Ringback tones
From TBwiki
According to Wikipedia, a Ring-back Tone (RBT) "is the audible ringing that is heard on the telephone line by the calling party after dialing and prior to the call being answered at the receiving end. This tone assures the calling party that a ringing signal is being sent on the called party's line, although the ring-back tone may be out of sync with the ringing signal. RBT is also known as Color Ringback Tone (CRBT)."
TelcoBridges and Ringback tones
Section under development
Deployments
In November 2008, TelcoBridges announced that Kingdom Telecom had successfully deployed a ringback tone solution with Henan Mobile, a subsidiary of China Mobile, with over 17 million subscribers. At the time of writing, the deployed system supported more than 4,000 E1 links.
