SIP Session Management 2

Question 1

Which SIP method is used to modify an existing session's parameters, such as changing the codec mid-call?

Accepted Answer

RE-INVITE

Answer

UPDATE

Answer

MODIFY

Answer

PATCH

Question 2

What is the purpose of the SIP UPDATE method compared to re-INVITE?

Accepted Answer

UPDATE modifies session state before the answer is received, avoiding hold

Answer

UPDATE terminates a session gracefully

Answer

UPDATE is used only for registration refresh

Answer

UPDATE replaces the ACK acknowledgment

Question 3

In a SIP dialog, what does the Route header set contain?

Accepted Answer

The list of proxy servers to traverse for in-dialog requests

Answer

The codecs negotiated during session setup

Answer

The sequence numbers of transmitted requests

Answer

The expiry time of the session

Question 4

What SIP response code indicates the session was successfully established?

Accepted Answer

200 OK

Answer

180 Ringing

Answer

202 Accepted

Answer

183 Session Progress

Question 5

Which SIP timer governs how long a UAC waits for a final response before retransmitting an INVITE?

Accepted Answer

Timer B

Answer

Timer A

Answer

Timer C

Answer

Timer D

Question 6

What is the function of the CSeq header in SIP session management?

Accepted Answer

Identifies the transaction method and sequence number within a dialog

Answer

Encrypts the session media stream

Answer

Stores the session expiration time

Answer

Routes requests through proxy servers

Question 7

When a SIP proxy inserts a Record-Route header, what is the primary reason?

Accepted Answer

To remain in the signaling path for subsequent in-dialog requests

Answer

To encrypt the SDP body

Answer

To indicate the session expiry time

Answer

To specify the codec preference order