How many tunes can you play at once?

The background music is played on up to eight background music channels per telephony trunk, while the prompts are played on the regular telephony channels (as shown in Figure 1). Any application can use any one of the music channels, so you can have all applications playing the same tune or up to eight applications can be playing different tunes; one application can play only one tune at a time, but can change from one tune to another.

However, the use of music channels does have a performance impact on the telephony channels.

In the example shown in Table 1, the applications on channels 1, 2, 4, 5, and 9 are playing Tune 1, while the applications on channels 3, 7, and 8 are playing Tune 2. At the same time, on channel 6, an application plays Tune 3, followed by Tune 4, finishing up with Tune 1.

The applications determine when to turn music on and off, and what music to play. However, the application cannot control the point at which the music starts and stops, it can only control the volume. It’s as if the application was tuning into a radio station that is already broadcasting music. A music channel continues to play the same tune until the last application turns it off. The music channel is then free to play a different tune.