Suppose you want to play audio to a caller when you receive an incoming call. Here’s how Plivo lets you do that.
Someone makes an incoming call to a Plivo number or SIP endpoint. Plivo looks up the URL configured for an application you’ve written that’s linked to the Plivo number or endpoint and makes a request to that URL. Your web application at that URL returns an XML document that provides instructions to the Plivo API on how the call should proceed.
In this example, Plivo works like an HTTP client that receives a call and requests instructions from your web application to control the call. By default, XML requests to your application are made via the HTTP
POST verb, but you can configure Plivo to make XML requests to your application via
POST by changing a configuration parameter.
You can set configuration parameters when making outbound calls or sending messages. For incoming calls and messages, Plivo uses the configuration attached to the application that’s linked to the phone number on which your incoming call or message is received.