Free CBNE Practice Questions

Question 1

After a switch replacement, receivers on one media VLAN play an IPv4 multicast feed when they join, then lose it four minutes later. The switch expires unrefreshed memberships after four minutes and drops multicast to ports without a membership entry. The encoder keeps transmitting. A capture spanning the failure shows membership reports but no membership queries; rejoining restores reception temporarily. What provides a lasting repair without flooding the VLAN?

Accepted Answer

Enable an IGMP querier to refresh receiver membership on the VLAN.

Answer

Add a static multicast route on the upstream router.

Answer

Extend the membership timeout to cover the longest scheduled program on the service.

Answer

Raise the encoder's multicast TTL to prolong packet lifetime.

Question 2

An archive supplies a program in a MOV container, but the playout server accepts only its specified MXF OP1a profile. Inspection confirms that the existing encoded video and audio, channel layout, and required metadata are compatible with that profile. No picture or sound processing is needed. Which preparation preserves the existing compressed essence without another encoding generation?

Accepted Answer

Rewrap the compatible streams into MXF OP1a without decoding and re-encoding them.

Answer

Transcode both streams into MXF at their existing bitrates.

Answer

Encode a higher-bitrate master before exporting the required MXF profile.

Answer

Play the program through SDI and recapture it using the server's approved MXF preset.

Question 3

During a live ST 2110 transmission, network A loses a burst of RTP packets. The SMPTE ST 2022-7 receiver obtains every matching packet from independent network B within its supported merge window. The merged output has no missing packets, and confidence monitoring remains clean. What accounts for the uninterrupted output?

Accepted Answer

The receiver fills gaps on A with timely copies of the same packets from B.

Answer

Parity carried on B reconstructs the payload missing from A.

Answer

The sender retransmits A's lost packets before the receiver releases each affected video frame.

Answer

The receiver divides each stream between the two paths and reassembles it at the output.

Question 4

An edit workstation at 10.42.8.25 belongs to the 10.42.8.0/24 VLAN and uses gateway 10.42.8.1. A storage server at 10.42.9.40 is on a separately routed VLAN; other workstations reach it normally. The failing workstation repeatedly broadcasts 'Who has 10.42.9.40?' instead of sending the traffic to its gateway. Which configuration error explains that behavior?

Accepted Answer

The workstation has a /16 mask and therefore treats 10.42.9.40 as on-link.

Answer

An outdated DNS answer is directing the workstation to the wrong server.

Answer

The gateway is preferring a higher-metric route to the storage VLAN.

Answer

The storage server has an incorrect return route to the workstation.

Question 5

Utility power has failed and the generator will not start. The UPS serving playout, automation, and shared storage reports six minutes of remaining runtime at the present load. An independently powered emergency program source is ready. The validated shutdown takes four minutes: stop automation and other storage clients, flush and shut down storage, then remove equipment power. Nonessential loads are already disconnected. What should the duty engineer initiate now?

Accepted Answer

Transfer to the emergency source and begin the validated shutdown sequence.

Answer

Keep playout running until two minutes remain, then start the orderly shutdown sequence.

Answer

Shut down shared storage first, leaving its automation clients running until power returns.

Answer

Select maintenance bypass so the UPS can conserve its remaining battery charge.

Question 6

A live RTP audio feed develops gaps during large file transfers. The sender maintains a steady packet cadence. At the receiver, a complete capture contains every transmitted packet, but late-arrival discards coincide with the gaps. Increasing the receive buffer from 10 ms to 30 ms removes the gaps; measured end-to-end delay remains below the service's 80 ms limit. What does this test establish?

Accepted Answer

Delay variation is causing late discards despite complete delivery of the transmitted packets.

Answer

Physical-link corruption is being repaired by retransmissions built into the RTP protocol.

Answer

The stream's average path latency exceeds the permitted end-to-end delay for the service.

Answer

The sender is producing audio at a sample rate that the receiver cannot support.

Question 7

A 3G-SDI path develops intermittent CRC errors after a rack move. Both endpoints support the required format. At unchanged settings, a short 75-ohm cable is error-free; reinstating the rack's patch path restores the errors. That path contains a newly fitted 50-ohm BNC adapter. The intervention most directly supported by this comparison is to:

Accepted Answer

Replace the adapter with a 75-ohm component and retest the installed path.

Answer

Reduce the source to HD-SDI and retain the installed patch path.

Answer

Add a second 75-ohm termination at the receiver.

Answer

Replace the receiver with one rated for a longer cable run at the same 3G-SDI rate.

Question 8

Tonight's episode is cleared for its scheduled terrestrial transmission in the station's territory, but its rights record expressly excludes internet distribution. Technical and editorial QC have passed. Automation can place a separately cleared filler on the web simulcast without changing the terrestrial output. How should the two outlets be scheduled?

Accepted Answer

Air the episode terrestrially and the cleared filler on the web simulcast.

Answer

Withdraw the episode from both outlets until internet distribution rights have been secured.

Answer

Air the episode on both outlets, restricting web access to viewers in the licensed territory.

Answer

Allow the live web simulcast but disable on-demand replay when the episode finishes.

Question 9

A six-drive RAID 10 volume is striped across three two-drive mirrors: drives 1-2, 3-4, and 5-6. Drives 2 and 5 fail before any rebuild begins. All other components remain healthy. Which statement correctly describes the surviving data and redundancy?

Accepted Answer

The data is readable; losing drive 1 or 6 would remove an entire mirror pair.

Answer

The data is already unavailable because any two simultaneous failures exceed RAID 10 protection.

Answer

The volume remains protected against the failure of any one of its four remaining drives.

Answer

The intact 3-4 mirror now contains the only complete copy of every stripe in the volume.

Question 10

Control traffic crosses a bureau's IPsec tunnel normally. Short UDP/RTP packets also arrive, but larger ones consistently disappear. Gateway diagnostics show that encapsulation would exceed the WAN path's MTU; fragmentation is prohibited. There are no congestion or access-rule drops. The encoder permits smaller RTP payloads without changing the encoded media. Which adjustment addresses the fault while retaining tunnel protection?

Accepted Answer

Reduce the RTP media payload per packet to fit the encapsulated path MTU.

Answer

Clamp TCP MSS at both IPsec tunnel endpoints.

Answer

Enable 9000-byte LAN frames without changing the WAN path.

Answer

Increase the jitter buffer so the receiver can wait longer for the missing large packets.

Free CBNE Practice Questions

Domain 1: Audio/Video over IP for Broadcast

Question 1

Question 2

Question 3

Domain 2: Digital Content Management

Question 4

Question 5

Domain 3: Video Systems in an IT World

Question 6

Question 7

Domain 4: Data Transmission Systems and Practices

Question 8

Domain 5: General PC Hardware, interconnection, and backup

Question 9

Question 10

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