Chapter 2 content

Question 1

What are the network applications?

Answer 1

These are applications which send or receive data from the internet to function to and from the application

Question 2

What is data generation and transmission? Draw schematics.

Answer 2

Generation: Data is the carrier of all kinds of information
Transmission: Data generated by apps must be transmitted between devices

Question 3

Describe the layers of the OSI network standard model.

Answer 3

7. Application layer: Provides an interface for apps
8. Presentation layer: Translates data format to ensure app-layer of one system can be identified by app layer of another system
9. Session layer: Establishes, manages, and terminates sessions between communicating parties
10. Transport layer: Establishes, maintains and cancels an end-end data transmission process; controls transmission speeds and adjusts data sequences
11. Network layer: Define logical addresses and transfers data from source to destinations
12. Data link layer: Encapsulates packed into frames, transmit frames in P2P or P2MP mode, and implements error checking
13. Physical layer: Transmits bitstreams over transmission media and defines electrical and physical specifications

Question 4

Describe the TCP/IP Reference model.

Answer 4

Application layer: format of messages, to transmit/receive messages from the internet
Transport layer: Receive message from app layer, add layer and take it to the network layer, and it provides end-end transmission
Network layer: Provides routing, the best path for data to be transmitted
Data link layer: Provide one-hop transmission
Physical layer: Transmit layers into the physical layer, e.g. electrical signal

Question 5

What are the common TCIP protocols with each layer?

Answer 5

Application:
Telnet, FTP, TFTP,SNMP,HTTP,SMTP,DNS,DHCP
Transport: TCP,DCP
Network layer: IP,ICMP,IGMP
Data link layer: Ethernet, PPP
Nothing for physical layer

Question 6

What is the standard protocol and what are the types of standard protocols?

Answer 6

Standard: Protocols which are public and developers need to use these:
-IETF: Developing and promoting internet protocols especially TCP/IP Protocol
-IEEE: Formulates standard in electronics, electrical and computer science, ethernet and Wi-Fi
-ISO: Formulation of computer network standards, such as OSI

Question 7

Explain according to the figures the data transmission according to the sender, intermediate and the receiver

Answer 7

1. Application layer: Search www.huawei.com, data is then transmitted to
2. Transport layer: Bcoz web page does not allow error TCP instead of UDP, therefore TCP header is added (contains important information such as the port number) and then the segment is transferred to the
3. Network layer: Will add IP header, add IP address and then sends to
4. Data link: Will see whole packet as payload and add a header (E.g. Source MAC address) and tail(CRC bits) to check if packet is correctly transmitted
5. Finally zeros and 1’s will be transmitted to media

Question 8

Describe the transmission on the intermediate network.

Answer 8

Check the figures

Question 9

What are the advantages of of the OSI and TCP/IP reference model?

Answer 9

1. Clear division of functions and boundaries
2. Function of each layer can be defined to comply to industry standard
3. Interfaces enable communication between hardware and software on various networks, improving compatability.