When a SIP user registers for the first time, the first message sent by the server is?

When a SIP user registers for the first time, the first message sent by the server is?
A . 401 Unauthorized
B. 486 Busy
C. 100 Tring
D. 200 0K

Answer: A

Subscribe
Notify of
guest
0 Comments
Inline Feedbacks
View all comments