The concept of an Automated Attendant or IVR is to answer an incoming call, then present some options for the caller to choose from via DTMFs, loop reading the menu while waiting for the caller to input their choice, execute the chosen option or tell the caller their input is wrong, and continue to loop until a timeout or a maximum number of loops is reached. Options can be as complex as desired, involving any kind of external interaction with databases, webservers, or other services. One form of option can be to gather a long string of DTMFs from the caller, for example, a numerical membership ID. Also, the caller must be able to jump from one menu to another containing different options, by choosing the appropriate option. Heck, you got the idea.