Inside Macintosh: Telephony /

Chapter 6 - Telephone Tools

About Telephone Tools

A telephone tool is a software module that manages the connection between a telephone network and applications or other software running on a Macintosh computer. On one end, the tool exchanges messages with the Telephone Manager. For example, when an application wants to place an outgoing call, it can use the TELConnect function. The Telephone Manager then sends one or more messages to the appropriate telephone tool to take the phone off hook and dial the specified number. The telephone tool accomplishes these tasks by calling the appropriate hardware driver. For instance, to place a call through an ISDN connection, the Telephone Manager would send messages to the Apple ISDN telephone tool, which then calls the driver for the ISDN card.

More than one telephone tool can be active at one time, if there are multiple network connections (that is, multiple telephone terminals) for a Macintosh computer.

IMPORTANT

Telephone tools differ from other Communications Toolbox tools in one important way: the main code resource of a telephone tool not only receives messages from the Telephone Manager, but also sends messages back (for example, to relay information from the network switch).