Lesson 4 - Chapter 1: TCP/IP Basics

Question 1

How many layers does the TCP/IP network model have?

Answer 1

5 (but in some models the bottom 2 are combined to make only 4 layers)

Question 2

Name the 5 layers of the TCP/IP network model from top to bottom

Answer 2

1. Application
2. Transport
3. Internet (Network)
4. Link (Network Interface)
5. Physical

Question 3

Describe the protocols used of the 5 layers of the TCP/IP network model

Answer 3

1. Application (HTTP, FTP, TELNET, DHCP, PING)
2. Transport (TCP, UDP)
3. Internet (Network) [IPv4, IPv6]
4. Link (Network Interface) [ARP, RARP, Ethernet]
5. Physical (Ethernet NICs, Switches)

Question 4

What does the Physical layer define? From what to what?

Answer 4

the standards for how data moves from the NIC to the network media (cables, wireless signals) and what switches/routers do with it

Question 5

Data travels through the physical layer in what format?

Answer 5

it travels in frames (that the physical layer requires)

Question 6

The Link layer is also called what 2 things?

Answer 6

Network Interface or Data Link layer

Question 7

What does the Link layer do?

Answer 7

It deals with the connection between the software and hardware only at the local network level and doesn’t route data to other networks

[Ethernet, ARP, RARP]

Question 8

What is the Internet layer also called?

Answer 8

the Network layer

Question 9

What happens at the Internet layer?

Answer 9

Uses IP addresses to route data between networks (uses destination network and destination device IP addresses)

[IPv4, IPv6]

Question 10

Does the Internet layer have error detection or correction features?

Answer 10

No

Question 11

What are the 2 major protocols that operate at the Transport layer?

Answer 11

UDP (connectionless protocol)
TCP (Transmission control protocol)

Question 12

What job does the TCP protocol do?

Answer 12

it uses back-and-forth confirmation messages and error checking to get one machine’s application data to another reliably/completely

Question 13

What communication rule does TCP have?

Answer 13

requires both the sending and receiving machines to acknowledge the other’s presence and readiness to send and receive data

[but it’s slower because of double-checking]

Question 14

Which protocol is known as a connection-oriented protocol?

Answer 14

TCP

Question 15

When would using the UDP protocol be best?

Answer 15

When you have a lot of data to send (perfection doesn’t matter) or systems are very close to each other (chances of problems are smaller)

(Much faster compared to TCP)

Question 16

What protocol does a web browser use?

Answer 16

browsers use HTTP which is a TCP-based protocol

(over 95% of all TCP/IP applications use TCP)

Question 17

What is the application layer?

Answer 17

this layer is where different apps that access the network operate (HTTP, HTTPS, FTP, SMTP, POP, IMAP, etc)

web browsers, file transfer, mail apps, etc

Question 18

What does encapsulate mean?

Answer 18

breaking the data down into appropriate-sized pieces, then wrapping those pieces in a container called a packet with instructions for the next layer

Question 19

Packets are like ___

Answer 19

envelopes

Each packet contains a header with the sending and receiving address and a piece of the data to be sent

Question 20

Name the specific name for each layer’s packet type

Application
Transport
Internet
Link
Physical

Answer 20

Application: Message
Transport: TCP segment or UDP datagram
Internet layer: IP datagram
Link layer: Frame
Physical layer: Frame

Question 21

Frames operate at the ____ level

Answer 21

Ethernet

Question 22

“Packet” means the same in the TCP/IP model as it does in the OSI model. T or F?

Answer 22

False, in OSI the term “packet” is limited to the data container created at Layer 3