Chapter 1

Question 1

Distributed Applications

Answer 1

apps which involve multiple end systems exchanging data with each other.

Question 2

Host vs. End-System

Answer 2

interchangeable terms for the agents that operate within the internet

Question 3

Access Technology Examples

Answer 3

1. DSL
2. Cable
3. Fibre
4. 3G
5. LTE
6. Ethernet
7. Wifi

Question 4

Guided Media vs. Unguided Media

Answer 4

solid medium vs. WLAN or satellite

Question 5

What speeds of Ethernet LAN are there?

Answer 5

10 Mbps, 100 Mpbs, 1 Gbps, 10 Gbps

Question 6

Max speeds of access technologies

Answer 6

up to 56 Kbps, bandwidth is dedicated; ADSL: up to 24 Mbps downstream and 2.5 Mbps upstream, bandwidth is dedicated; HFC, rates up to 42.8 Mbps and upstream rates of up to 30.7 Mbps, bandwidth is shared. FTTH: 2-10Mbps upload; 10-20 Mbps download; bandwidth is not shared.

Question 7

What is store-and-forward?

Answer 7

every packet must be received in a node before being transmitted to a subsequent node.

Question 8

Output buffer/queue

Answer 8

stores all outgoing packets before sending them.

Question 9

Queuing Delay

Answer 9

a delay caused by waiting for a busy link and being stored in a output buffer. can lead to lost packets if it runs out of space.

Question 10

Forwarding Table

Answer 10

maps destination addresses to the router’s outbound link.

Question 11

Packet Switch vs. Circuit Switch

Answer 11

packet switch involves a shared medium, where a request/response is important. circuit switch is a direct line between two communicators - more resource heavy, but direct and dependable, with a guaranteed bandwidth.

Question 12

Circuit

Answer 12

When two end users on a network maintain a persistent connection throughout their communication.

Question 13

FDM

Answer 13

Frequency-division multiplexing.

Question 14

TDM

Answer 14

Time-division multiplexing.

Question 15

What are the delay components of a packet sending action?

Answer 15

• processing delay
• transmission delay
• propagation delay
• queueing delay

Question 16

Define processing delay

Answer 16

time required to examine a packet’s header and determine where it goes

Question 17

Define transmission delay

Answer 17

it is L/R where L is the length in bits and R is the transmission rate.

Question 18

define propagation delay

Answer 18

Physical movement delay, dependent on the medium. usually between 2e8 m/s or 3e8m/s speed of lightish. it is d/s where d is the distance and s is the speed.

Question 19

define queueing delay

Answer 19

the delay a packet experiences while it waits to be transmitted onto the link.

Question 20

name the layers

Answer 20

application layer
transport layer
network layer
link layer
physical layer

Question 21

application layer

Answer 21

where the network applications reside. includes HTTP, SMTP, and FTP. uses DNS. packets are called a MESSAGE

Question 22

transport layer

Answer 22

Transports application-layer messages between app endpoints. Uses TCP and UDP. Packets are called a SEGMENT

Question 23

network layer

Answer 23

Uses the IP protocol to move packets from one host to another. Contains the routing protocols. Packets are called DATAGRAMS.

Question 24

link layer

Answer 24

Interfaces between the network and physical layer - prepares the DATAGRAM for delivery from the current link to the next link. Ethernet, WiFi are examples of link layer. packets are called FRAMES.

Question 25

physical layer

Answer 25

The actual cable or air that the BITS are traveling through.

Question 26

Malware

Answer 26

malicious software used to compromise your computer

Question 27

Viruses

Answer 27

malware that require some level of user interaction.

Question 28

Worms

Answer 28

malware that can enter your computer without any explicit interaction.

Question 29

Name three DDOS attack examples

Answer 29

• Vulnerability attack
• Bandwidth Flooding
• Connecting flooding

Question 30

HFC

Answer 30

Hybrid-fibre-coaxial - many cable connections to the home are a combo of fibre and coax

Question 31

What are valid ethernet physical forms?

Answer 31

Twisted-pair copper wire

fibre optic