Wireshark.....401 error


Hi, does anybody know why when i make a call i have an ( SIP/2.0 401 Unauthorized) error and after 2 sec it says SIP/2.0 200 OK…in Wireshark

I know is not a big thing but i try to understant why.



it’s normal, then the negotiation starts and everything goes back to normal.


Thanks damiano70 for the information


Register - 401 . new register
invite - 407 - new invite encrypted


When you an INVITE is sent, the SIP server will challenge it with a 401. This causes the device sending the INVITE to re-send, but this time to include the authentication details so the server can validate the requesting device before allowing the call to be handled.

Damiano said as much, just in fewer words.