CDN Video Streaming & Media Delivery 3

Question 1

In MPEG-DASH, what does the 'MPD' file contain?

Accepted Answer

Media Presentation Description with all available representations and segment URLs

Answer

The MPD (Media Presentation Description) is DASH's manifest file that describes all available quality representations, segment templates, and timing information.

Question 2

A sports broadcaster wants to minimize live stream latency to under 3 seconds. Which technology stack best achieves this?

Accepted Answer

Low-Latency HLS (LL-HLS) with partial segments

Answer

LL-HLS uses partial segments and blocking playlist reloads to achieve sub-3-second latency while maintaining CDN scalability.

Question 3

What is 'just-in-time packaging' (JIT) in the context of CDN video delivery?

Accepted Answer

Segments are transcoded and packaged at the edge only when a viewer requests them

Answer

JIT packaging generates adaptive streaming segments on-demand at the CDN edge or origin, eliminating the need to pre-package every format and bitrate.

Question 4

Which HTTP header is primarily used to instruct CDN edges on whether to cache a video segment and for how long?

Accepted Answer

Cache-Control

Answer

The Cache-Control header with directives like max-age tells CDN edge nodes how to cache responses and for how long.

Question 5

A video platform notices that 4K stream requests are frequently missing CDN cache and hitting origin. What is the most likely cause?

Accepted Answer

High bitrate variants have low request frequency, reducing cache hit rates

Answer

4K content is less popular than lower resolutions, so its segments are requested less frequently, leading to cache evictions and more origin fetches.

(CDN) Content Delivery Network Certification Practice Test

(CDN) Content Delivery Network Certification Practice Test

CDN Video Streaming & Media Delivery 3