Practice Test Geeks(CDN) Content Delivery Network Certification Practice Test
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Video Streaming & Media Delivery Flashcards

7 cards from real CDN practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Video Streaming & Media Delivery flashcards as text

  1. Which CDN technique reduces startup latency for live video streams by pre-positioning the first few segments at edge nodes before viewers request them?

    Answer: Segment prefetching

    Segment prefetching pushes the initial video segments to edge nodes proactively, reducing the time-to-first-frame for live streams.

  2. In HLS streaming, what is the purpose of the EXT-X-DISCONTINUITY tag in a playlist?

    Answer: Marks a break in stream continuity such as an ad insertion point

    EXT-X-DISCONTINUITY signals that there is a break in continuity between the preceding and following media segments, commonly used at ad insertion boundaries.

  3. A CDN reports a high 'rebuffering ratio' for video streams. Which metric most directly indicates the severity of this problem?

    Answer: Percentage of total playback time spent buffering

    The rebuffering ratio — buffering time divided by total playback time — directly measures how often viewers experience stalls relative to watch time.

  4. Which protocol allows CDN edges to push video segments to viewers over a single persistent connection without repeated HTTP polling?

    Answer: HTTP/2 Server Push

    HTTP/2 Server Push enables the server to proactively send resources to clients over the same connection before they are explicitly requested.

  5. What is the role of a 'packaging service' in a video CDN pipeline?

    Answer: Converts encoded video into adaptive streaming formats like HLS and DASH

    A packaging service takes encoded video and wraps it into adaptive streaming manifests and segment formats (HLS, DASH) suitable for CDN delivery.

  6. When a viewer switches from a high-bitrate to a low-bitrate rendition mid-stream, which ABR behavior is occurring?

    Answer: Downshift or quality downgrade

    An ABR downshift occurs when the player detects insufficient bandwidth and switches to a lower-bitrate rendition to prevent rebuffering.

  7. Which CDN configuration setting controls how long a video segment is stored at an edge node before it is considered stale?

    Answer: Cache TTL (Time-To-Live)

    Cache TTL defines how long cached content remains valid at the edge before the CDN must revalidate or re-fetch it from origin.

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