CST IP Camera & PoE Networking 2 — Questions and Answers
Question 1: A PoE switch port is rated at 15.4W (802.3af). An IP camera requires 18W. What is the correct solution?
- Use a longer Cat6 cable to reduce power draw
- Replace the switch with one supporting 802.3at (PoE+) (Correct answer)
- Add a PoE injector between the switch and camera
- Enable LLDP on the switch port
Correct answer: Replace the switch with one supporting 802.3at (PoE+)
802.3at (PoE+) delivers up to 30W per port, sufficient for cameras requiring more than the 15.4W limit of 802.3af.
Question 2: What does ONVIF Profile S standardize for IP surveillance cameras?
- Video analytics and metadata streaming
- PTZ control, video streaming, and event handling (Correct answer)
- Edge storage and SD card management
- License plate recognition interfaces
Correct answer: PTZ control, video streaming, and event handling
ONVIF Profile S standardizes interoperability for basic IP camera functions including video streaming, PTZ control, and event handling.
Question 3: Which subnet mask allows up to 254 usable host addresses on a single network segment?
- 255.255.0.0
- 255.255.255.0 (Correct answer)
- 255.255.255.128
- 255.0.0.0
Correct answer: 255.255.255.0
A /24 mask (255.255.255.0) provides 256 addresses minus 2 reserved, yielding 254 usable hosts.
Question 4: An IP camera is not discovered by the VMS after installation. The camera has a self-assigned 169.254.x.x address. What is the most likely cause?
- The camera firmware is outdated
- DHCP is unavailable and no static IP was configured (Correct answer)
- The switch port VLAN is misconfigured for multicast
- The camera's MAC address is blocked by the firewall
Correct answer: DHCP is unavailable and no static IP was configured
A 169.254.x.x (APIPA) address indicates the camera failed to obtain an IP from DHCP and has no static address configured.
Question 5: What is the purpose of the RTSP protocol in an IP camera system?
- Assigning IP addresses to cameras dynamically
- Streaming live video from cameras to clients (Correct answer)
- Encrypting video data between camera and NVR
- Synchronizing camera clocks over the network
Correct answer: Streaming live video from cameras to clients
RTSP (Real Time Streaming Protocol) is used to establish and control media sessions for live video streaming from IP cameras.
Question 6: A technician needs to prevent an IP camera VLAN from accessing the corporate LAN. Which device feature should be configured?
- Spanning Tree Protocol (STP)
- Inter-VLAN routing ACL or firewall rule (Correct answer)
- DHCP snooping on the camera VLAN
- Port mirroring on the uplink port
Correct answer: Inter-VLAN routing ACL or firewall rule
An ACL or firewall rule applied to inter-VLAN routing blocks traffic from the camera VLAN from reaching the corporate network.
Question 7: What is the maximum cable length specified by TIA-568 for a horizontal Cat5e/Cat6 run in a structured cabling system?
- 50 meters
- 90 meters (Correct answer)
- 100 meters
- 150 meters
Correct answer: 90 meters
TIA-568 specifies a maximum 90-meter horizontal cable run, with 10 meters reserved for patch cords, totaling a 100-meter channel.
CST IP Camera & PoE Networking 2
A PoE switch port is rated at 15.4W (802.3af).
An IP camera requires 18W.
What is the correct solution?