CST IP Camera & PoE Networking 3 — Questions and Answers
Question 1: Which H.264 profile is most commonly used in IP cameras to balance compression efficiency and hardware compatibility?
- Baseline Profile
- Main Profile
- High Profile (Correct answer)
- Extended Profile
Correct answer: High Profile
High Profile provides the best compression efficiency and is widely supported by modern IP cameras and NVRs for surveillance applications.
Question 2: A PoE switch has a total power budget of 120W with 8 ports. All 8 cameras draw 15W each. What happens when the 8th camera is connected?
- All cameras reboot to redistribute power
- The 8th camera does not receive PoE power (Correct answer)
- The switch automatically upgrades to PoE+ mode
- The switch shuts down to prevent damage
Correct answer: The 8th camera does not receive PoE power
When total demand (8×15W=120W) reaches the switch's power budget, the last connected device may be denied power depending on port priority settings.
Question 3: What does the term 'codec' refer to in IP camera video transmission?
- The network cable category used to transmit video
- The algorithm that compresses and decompresses video data (Correct answer)
- The physical connector type on the camera
- The encryption method used for secure streaming
Correct answer: The algorithm that compresses and decompresses video data
A codec (coder-decoder) is the algorithm that compresses video for transmission and decompresses it for playback, such as H.264 or H.265.
Question 4: Which IP camera resolution is referred to as '4MP'?
- 1920×1080 pixels
- 2560×1440 pixels
- 2688×1520 pixels (Correct answer)
- 3840×2160 pixels
Correct answer: 2688×1520 pixels
4MP typically refers to 2688×1520 resolution (approximately 4 megapixels), commonly used in surveillance cameras.
Question 5: A network switch is configured with 802.1Q VLAN tagging. What is the function of the 'native VLAN' on a trunk port?
- It carries tagged traffic from all VLANs simultaneously
- It handles untagged frames received on that trunk port (Correct answer)
- It is reserved exclusively for management traffic
- It encrypts frames before sending them over the trunk
Correct answer: It handles untagged frames received on that trunk port
The native VLAN on an 802.1Q trunk port carries untagged frames; any untagged traffic is assigned to the native VLAN by default.
Question 6: What is the primary advantage of using H.265 (HEVC) over H.264 for IP camera storage?
- H.265 supports higher frame rates than H.264
- H.265 requires approximately 50% less storage for equivalent quality (Correct answer)
- H.265 eliminates the need for an NVR
- H.265 is compatible with analog cameras
Correct answer: H.265 requires approximately 50% less storage for equivalent quality
H.265 achieves approximately 50% better compression than H.264 at the same visual quality, significantly reducing storage requirements.
Question 7: When configuring a static IP address on an IP camera, which four parameters are typically required?
- IP address, subnet mask, default gateway, DNS server (Correct answer)
- IP address, MAC address, SSID, port number
- IP address, subnet mask, VLAN ID, port number
- IP address, default gateway, RTSP port, HTTP port
Correct answer: IP address, subnet mask, default gateway, DNS server
Static IP configuration requires at minimum an IP address, subnet mask, default gateway, and DNS server to enable network communication.
CST IP Camera & PoE Networking 3
Which H.264 profile is most commonly used in IP cameras to balance compression efficiency and hardware compatibility?