CCTV Network and IP Video 4 — Questions and Answers
Question 1: What is 'substream' or 'secondary stream' functionality in an IP camera?
- A backup stream sent to a secondary NVR
- A lower-resolution stream used for live view while the main stream records (Correct answer)
- An encrypted stream reserved for forensic use
- A stream transmitted over a secondary network interface
Correct answer: A lower-resolution stream used for live view while the main stream records
Dual-streaming lets the camera send a lower-resolution substream for live monitoring while simultaneously recording the full-resolution main stream.
Question 2: Which cybersecurity practice is MOST critical when deploying IP cameras on a network?
- Enabling DHCP on all cameras
- Changing default usernames and passwords on every device (Correct answer)
- Using only Wi-Fi cameras to avoid cable vulnerabilities
- Disabling HTTPS to reduce processing overhead
Correct answer: Changing default usernames and passwords on every device
Default credentials are the leading attack vector for IP cameras; changing them immediately is the single most critical security step.
Question 3: What does 'bitrate' measure in an IP video stream?
- The number of frames captured per second
- The amount of data transmitted per unit of time (Correct answer)
- The resolution of each video frame
- The compression ratio applied to each frame
Correct answer: The amount of data transmitted per unit of time
Bitrate measures the volume of data (bits) transmitted per second, directly affecting video quality and bandwidth consumption.
Question 4: In IP camera networking, what is a 'managed switch' primarily used for compared to an 'unmanaged switch'?
- Managed switches provide more PoE ports than unmanaged switches
- Managed switches allow configuration of VLANs, QoS, and port mirroring (Correct answer)
- Managed switches are always more cost-effective for small installations
- Managed switches eliminate the need for a router
Correct answer: Managed switches allow configuration of VLANs, QoS, and port mirroring
Managed switches offer advanced configuration options like VLANs, QoS prioritization, SNMP monitoring, and port mirroring that unmanaged switches lack.
Question 5: Which compression technique does H.264 use to reduce file size by only encoding changes between frames?
- Intra-frame compression (I-frames only)
- Inter-frame compression using P-frames and B-frames (Correct answer)
- Lossless compression using LZ77
- Run-length encoding (RLE)
Correct answer: Inter-frame compression using P-frames and B-frames
H.264 uses inter-frame compression with P-frames (predicted) and B-frames (bi-directional) that store only the differences from reference frames.
Question 6: A customer wants to access their IP camera system remotely over the internet. Which solution provides the most secure access?
- Port forward camera HTTP ports directly through the firewall
- Use a VPN tunnel to the site network (Correct answer)
- Enable UPnP on the router for automatic port mapping
- Share the camera's public IP and credentials via email
Correct answer: Use a VPN tunnel to the site network
A VPN tunnel encrypts all traffic between the remote user and the site network, avoiding the exposure of camera ports directly to the internet.
Question 7: What is the purpose of Network Time Protocol (NTP) in an IP camera system?
- Synchronize camera clocks for accurate timestamps on recorded footage (Correct answer)
- Reduce network latency for live video streams
- Provide automatic IP address assignment to cameras
- Enable remote firmware updates to cameras
Correct answer: Synchronize camera clocks for accurate timestamps on recorded footage
NTP synchronizes all cameras and recording devices to the same accurate time, ensuring timestamps are consistent and legally defensible.
CCTV Network and IP Video 4
What is 'substream' or 'secondary stream' functionality in an IP camera?