Answer Call Functionality
If an endpoint (SIP phone) supports remote CTI control by providing the SIP extensions event package known as "BroadSoft" SIP extensions, SIP Server allows SIP Server clients to answer the call by means of the TAnswerCall request. When responding to the TAnswerCall request, SIP Server will send an event with the header "Event" and a header value of "talk" to the SIP phone, in a ringing state of NOTIFY. This event instructs the SIP phone to answer the call without human interference. Note that SIP phones that support such an event package should send a 180 Ringing message header of "Allow-Events:", which should contain "talk" inside its value.