In a Web telephony session, users can make phone calls
using the ClicktoCall widget in their Web browsers. The call flow
diagram illustrates the Communications Enabled Applications (CEA)
call flow.
Note: The system application must first be configured with the IP
private branch exchange (PBX) address.
The following configuration applies to this call flow:
- A user clicks the ClickToCall widget, which sends an HTTP REST
request.
- The Web container calls the system application.
- An HTTP servlet interprets the REST request.
- The system application sends SIP messages to the IP PBX using
the ECMA TR/87 standard protocol.
Restriction: The IP PBX
must support the ECMA TR/87 protocol.
- The computer telephony integration (CTI) application contacts
the IP PBX through SIP.
- The CTI application sends a call request to the IP PBX.
- The IP PBX notifies the user agent client (UAC) to call the user
agent server (UAS).
- A call is established between the two users.
Note: UAC and UAS
are SIP instances.
Figure 1. CEA call flow