$1\mathrm{.}4.$WHAT IS DASH?

In DASH $($Dynamic$,$ Adaptive Streaming over HTTP$),$ a server divides a video file into chunks

that $...($pick best completion from below$)$

a$....$ are stored, each encoded at multiple rates $($video quality$).$ The client receives multiple

video chunks $($encoded at different rates$)$ and plays out the chunks that best fit the screen size.

b$....$ are stored, each encoded at multiple rates $($video quality$).$ The client plays the video

chunk$-$by$-$chunk, with each chunk requested at encoding rate that fits the available bandwidth at

the time.

c$....$ allow premium users to avoid watching chunks that contain commercials.

d$....$ are download smallest$-$chunk$-$first in order to maximize the number of chunks received.

e$....$ are downloaded just before their playout time. Chunking is used primarily because a

viewer may jump around $($e$.$g$.,$ fast forward$)$ in a video.

$1\mathrm{.}5$ CONDITIONAL HTTP GET.

What is the purpose of the conditional HTTP GET request message?

a$.$ To allow a server to only send the requested object to the client if the server is not

overloaded.

b$.$ To allow a server to only send the requested object to the client if the client has never

requested that object before.

c$.$ To allow a server to only send the requested object to the client if this object has changed

since the server last sent this object to the client.

d$.$ To allow a server to only send the requested object to the client if the client is authorized

to received that object.

$(28$pts$,4$ pts each$)2.$ Multiple Choice

$2\mathrm{.}1$ WHAT IS A NETWORK OF NETWORKS?

When we say that the Internet is a "network of networks," we mean?

a$.$ The Internet is the largest network ever built.

b$.$ The Internet is made up of a lot of different networks that are interconnected to each other.

c$.$ The Internet is the fastest network ever built.

d$.$ The Internet is made up of access networks at the edge, tier$-1$ networks at the core, and

interconnected regional and content provider networks as well.