CDN Video Streaming & Media Delivery 2

Question 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?

Accepted Answer

Segment prefetching

Answer

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

Question 2

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

Accepted Answer

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

Answer

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

Question 3

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

Accepted Answer

Percentage of total playback time spent buffering

Answer

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

Question 4

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

Accepted Answer

HTTP/2 Server Push

Answer

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

Question 5

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

Accepted Answer

Converts encoded video into adaptive streaming formats like HLS and DASH

Answer

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

(CDN) Content Delivery Network Certification Practice Test

(CDN) Content Delivery Network Certification Practice Test

CDN Video Streaming & Media Delivery 2