Question 1: What does the SIP "Via" header do in an INVITE request?

• A) Specifies the codec list for media negotiation
• B) Identifies the transport path and ensures responses follow the same route
• C) Defines encryption parameters for SRTP
• D) Lists all allowed SIP methods

Reveal Answer

Answer: B) Identifies the transport path and ensures responses follow the same route
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Question 2: What is the purpose of the "Call-ID" header in SIP?

• A) It carries the session description (SDP)
• B) Uniquely identifies a SIP session across dialogs
• C) Indicates media directionality
• D) Controls session expiration timing

Reveal Answer

Answer: B) Uniquely identifies a SIP session across dialogs
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Question 3: What does the "Record-Route" header ensure?

• A) That media is encrypted using SRTP
• B) That all in-dialog requests follow the same signaling path as the initial request
• C) That RTP streams bypass the SIP proxy
• D) That endpoints exchange public keys

Reveal Answer

Answer: B) That all in-dialog requests follow the same signaling path as the initial request
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Question 4: Which SDP attribute indicates both parties can send and receive media?

• A) a=sendrecv
• B) a=sendonly
• C) a=inactive
• D) a=recvonly

Reveal Answer

Answer: A) a=sendrecv
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Question 5: When CUCM provides Music on Hold, which of these might appear in the SDP?

• A) c=IN IP4 0.0.0.0
• B) c=IN IP4 (MOH server IP) with a=sendonly
• C) Both of the above
• D) Neither of the above

Reveal Answer

Answer: B) c=IN IP4 (MOH server IP) with a=sendonly
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Question 6: In SDP, what is the purpose of "a=rtpmap"?

• A) To map dynamic payload types to specific codec names and parameters
• B) To specify encryption key details
• C) To declare media inactivity
• D) To indicate session expiration time

Reveal Answer

Answer: A) To map dynamic payload types to specific codec names and parameters
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Question 7: What does the "Contact" header in SIP specify?

• A) The SIP URI for future requests within this dialog
• B) The maximum hops allowed
• C) The event package supported
• D) The codec selection for RTP

Reveal Answer

Answer: A) The SIP URI for future requests within this dialog
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Question 8: Which SDP attribute defines media encryption parameters?

• A) a=crypto
• B) a=rtpmap
• C) a=sendonly
• D) a=setup

Reveal Answer

Answer: A) a=crypto
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Question 9: What does the SIP "Max-Forwards" header control?

• A) The lifetime of the session
• B) The number of proxies or hops a request may traverse
• C) The accepted media types
• D) The fingerprint for DTLS verification

Reveal Answer

Answer: B) The number of proxies or hops a request may traverse
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Question 10: In SDP, what does the "a=inactive" attribute indicate?

• A) Both sides will exchange RTP streams
• B) Neither side will send or receive media
• C) The stream is encrypted
• D) The bandwidth limit is set to zero

Reveal Answer

Answer: B) Neither side will send or receive media
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Question 11: In SIP, what does the "Supported" header list?

• A) The optional SIP extensions that the UA supports
• B) The media capabilities of the endpoint
• C) The bandwidth for the session
• D) The session encryption method

Reveal Answer

Answer: A) The optional SIP extensions that the UA supports

Example Supported header: Supported: X-cisco-srtp-fallback,X-cisco-sis-10.0.0,X-cisco-supports-AR
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Question 12: What does the "P-Asserted-Identity" header in SIP provide?

• A) The public identity asserted by a trusted SIP proxy
• B) The encryption fingerprint for SRTP
• C) The DNS resolution result
• D) The maximum call duration

Reveal Answer

Answer: A) The public identity asserted by a trusted SIP proxy
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Question 13: In SIP, what is the role of the "Allow-Events" header?

• A) Lists supported SIP request methods
• B) Lists supported SIP event packages
• C) Defines the MIME types accepted
• D) Specifies the next hop IP

Reveal Answer

Answer: B) Lists supported SIP event packages
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Question 14: What does the "Expires" header control in a SIP request?

• A) The maximum number of hops allowed
• B) The validity duration of a SIP request like REGISTER or INVITE
• C) The media negotiation method
• D) The session encryption key

Reveal Answer

Answer: B) The validity duration of a SIP request like REGISTER or INVITE
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Question 15: In SDP, what does the "b=AS" attribute specify?

• A) The maximum allowed audio sample rate
• B) The allocated session bandwidth in kilobits per second
• C) The number of allowed SIP transactions
• D) The encryption algorithm

Reveal Answer

Answer: B) The allocated session bandwidth in kilobits per second
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