Introduction to the VoIP HTTP API


To understand how the HTTP API works, first take a look at Figure 1. This figure illustrates a call coming from the outside and it helps to understand the terms used in the documentation.

call arriving to ozeki phone system
Figure 1 - Call arriving to Ozeki Phone System

The call is made by a PSTN phone (+36 1 111 111), to our telephone line (+36 1 222 222) provided by the telecom company. We call this line outside line. The call is forwarded to the extension (1001) by the Ozeki Phone System PBX. The extension is a desktop phone in the office. The Ozeki Phone System PBX serves as an "automated telephone switch board" between the outside line (+36 1 222 222) and the extensions (1001 and 1002). The PBX accepts the call on the outside line (+36 1 222 222) and forwards the call to the appropriate extension. In this case we use the following terms:

  • caller=+36 1 111 111 (PSTN telephone)
  • callee line=+36 1 222 222 (PSTN telephone line provided by the telecom company = outside line)
  • call leg 1 = The call from +36 1 111 111 to +36 1 222 222
  • call leg 2 = The call from +36 1 222 222 to extension 1001
  • call = The call from +36 1 111 111 to extension 1001

The above terms are important to understand the HTTP API. The HTTP API provides a way for a business application (Figure 2) to interact with the above procedure. The business application can receive notifications about call related events and it can interact with the call. The interactions are safe and secure. You can use username and password authentication in every command you interact with Ozeki Phone System.

ozeki phone system http api interface
Figure 2 - Ozeki Phone System HTTP API Interface

HTTP requests are sent and responses are received according to the HTTP/1.1 protocol specification. HTTP GET and HTTP POST requests can be sent to the phone system. HTTP responses are returned using HTTP 200 OK status header. Responses to HTTP request are in XML response format.
Notifications are sent from the phone system to a given URL only in a HTTP POST request. You can write a HTTP response to the notifications in OzML.

HTTP API functionality

The HTTP API in the Ozeki Phone System provides call control and messaging functionality. Both features provide a set of methods a HTTP Business Application can invoke using HTTP client requests, and a set of events triggered by the Ozeki Phone System PBX. Check out the HTTP request commands, event notifications and OzML commands of the API:


HTTP request commands
OzML commands
Event notifications

More information