Motivation

Question 1

a key performance bottleneck

for modern web transfers

Answer 1

TCP’s handshake

Question 2

requests sent on new TCP connections

Answer 2

cold requests

Question 3

requests that reuse TCP connections

Answer 3

warm requests

Question 4

supports persistent HTTP connections

Answer 4

HTTP/1.1

Question 5

over 33% of requests made by Chrome are sent on newly

created TCP connections

Answer 5

even though it uses HTTP 1.1 persistent

connections.

Question 6

The restricted effectiveness of persistent

connections is due to several factors

Answer 6

Browsers today often
open tens of parallel connections to accelerate page downloads,
which limits connection reuse. Domain sharding or
the placement of resources on different domains by content
providers to increase parallelism in loading web pages also
exacerbates this issue. In general, hosts and middle-boxes
(NATs) also terminate idle TCP connections to minimize
resource usage.

Question 7

These browsers close idle connections after mere seconds to

conserve power.

Answer 7

Major mobile

browsers

Question 8

has a limit of 6 parallel connections per domain

Answer 8

Chrome

Question 9

has a lower

RTT and processing time than many other websites.

Answer 9

Google