{
	"answer": "200 OK"
}
ValueDescription
200 OKSession Description Protocol (SDP) message that is sent by an answerer in response to an offer that is received from an offerer.
183 Session ProgressEstablishes media (SDP) but does not answer. Is equivalent to a SIP status code 183 with SDP.
180 RingingIs equivalent to a SIP status code 180 Ringing without SDP.

You can use only sip status code as a value.