I am planning to design a alarm control panel for my house. I ve managed to interface motion detectors,
magnetic contacts, smoke detectors as input and siren, flashing lights as output via optocouplers directly from T89C51RD2 pins. It's working OK.

Now I want to add it to the Public Telephone Network with the following features by using T89C51RD2 micro controller only.

Someone suggested that I should use a voice dialer which should be triggered by a door/window,motion detector etc.with a feature to dial four numbers,
call and play security alert message
(pre- recorded message) If first dialed number does't answer should dial the next and so on. It should
not be fooled by answering machine.

Kindly suggest, how to proceed with this project.
What are the additional parts I will need ?

Thanks in advance

Yogesh