A web callback is a way to initiate a telephone call from a web request, for example by clicking on a link or by sending a HTTP request with a program such as curl. SIPSorcery provides two slightly different approaches for intiating web callbacks.
After logging onto the AJAX Portal click on the Web Callbacks menu option. The page allows new callbacks to be created as well as existing ones to be updated of deleted. Existing callbacks can be initiated by clicking on the "place call" link. When the link is clicked on the SIPSorcery application server will attempt to dial the first call leg and if it is successfully answered it will successfully dial the second call leg.
The dial strings used in the callbacks are the same foramt as the dial strings used in the sys.Dial command in a Ruby dial plan. This means they can include multiple call legs and additional call control options.
The Web Callback feature can be used to initiate a callback using a HTTP GET request. The steps involved are:
At the moment the only discretionary parameter for a web callback is the number parameter. By putting extra information in that parameter it is possible to use it within the webcallback dialplan.
An example a making a web callback using extra information in the number parameter is shown in the example below.