T1 and T2 are two terminals in the same SC node area (authentication policy enabled) and both have successfully registered using the SIP protocol. When T1 calls T2’s number through the SIP protocol, the SC replies to T1 ""100 trying"" message, which of the following response codes will SC reply to T1 immediately afterwards?

T1 and T2 are two terminals in the same SC node area (authentication policy enabled) and both have successfully registered using the SIP protocol. When T1 calls T2’s number through the SIP protocol, the SC replies to T1 ""100 trying"" message, which of the following response codes will SC reply to T1 immediately afterwards?
A . 403
B . 408
C . 404
D . 407

View Answer

Answer: D