SSCA SIP Headers 3

Question 1

Which SIP header is used to route a request through a specific set of proxies in order?

Accepted Answer

Route

Answer

The Route header specifies a pre-determined list of SIP proxies through which the request must pass.

Question 2

What does a SIP Warning header provide?

Accepted Answer

Additional information about why a response was generated, beyond the status code

Answer

The Warning header carries human-readable information about issues encountered when processing a request, such as incompatible session descriptions.

Question 3

Which header would a SIP proxy add to indicate the address at which it can be reached for future requests?

Accepted Answer

Record-Route

Answer

A proxy inserts a Record-Route header with its own URI so it remains in the signaling path for subsequent in-dialog requests.

Question 4

What is the purpose of the Replaces header in SIP?

Accepted Answer

To replace an existing dialog with a new INVITE

Answer

The Replaces header allows a new INVITE to atomically replace an existing confirmed or early dialog, used in call transfer scenarios.

Question 5

What information does the P-Asserted-Identity header carry?

Accepted Answer

The verified identity of the user sending the request, as asserted by a trusted network element

Answer

P-Asserted-Identity carries the authenticated identity of the originating user, inserted by a trusted SIP proxy after verifying credentials.

(SSCA) Sip School Certified Associate Practice Test