Introduction to Networking

Question 1

Why Networking needed?

Answer 1

After inventing personal computers those computers needed to share resources(share printers, share data storage without maintainingduplicats of same data on different computers)

Question 2

Reasons that motivated Networking of computer

Answer 2

Share expensive resources
To permit the distribution of workload
Concurrent/parallel computing, client-server computing, fault tolerance
To facilitate the transfer of information
Database transactions, electronic mail and networked distribution of data archives

Question 3

Data communication

Answer 3

Process of transferring digital data in a reliable and efficient manner.

Question 4

Data communication model

Answer 4

Binary-> analog-> Binary

Question 5

How computers connected to network

Answer 5

External or internal Modem
Network interface card(NIC)

Question 6

What’s network?

Answer 6

Two or more computer systems connected together using data communication link is called network

Question 7

Computer networks depending on technology, structure are of coverage

Answer 7

Technology-
Peer to peer
Client service

Structure -
Star, bus, ring

Area -
Pan, wan, lan, man

Question 8

Protocol

Answer 8

Set of agreed rules between communicating parties on how communication is proceed

Question 9

Peer entities

Answer 9

Entities in the corresponding layers on different computer systems

Question 10

Interface

Answer 10

Difine which operations and services the lower layer makes available to the adjacent upper layer

Question 11

Flow control

Answer 11

Speed of the sender may differ from the receiver. In such case both sender and receiver should agree on how to send and receive data without them being lost. Receiver’s should acknowledge receipt of data indicating receiver’s current situation.

Question 12

Error control

Answer 12

Receiver should tell the sender which message were correctly received or not so that sender may resend them or discard the whole message.

Question 13

Routing

Answer 13

Function of facilitating a path from a source node on one network to a destination node on another network.

Question 14

OSI Reference model
7. Applications layer

Answer 14

Provide common interface for different user applications
Information maintained-
User data
Portacol-
Http, pop3, soap
Device-
Gateway

Question 15

presentation layer

Answer 15

Concerned with the syntax and semantics of the information transmitted
Information maintained-
Message
Portacol-
ASC II, GIF, JPAG
Device-
Gateway

Question 16

Session layer

Answer 16

Established and manages end-user connections
Eg- allows user on different machines to establish sessions between them
Eg- a session might be used to allow a user to log into a remote time sharing system or to transfer a file between two machines
Information maintained-
_
Portacol-
RPC
Device-
Gateway

Question 17

Transport layer

Answer 17

Provide the functions necessary to guarantee a reliable network link.
Provide error recovery and flow control between two end points of the network connection.
Insulates upper layers(5-7) from having to deal with the complexity of layers 1 - 3
Information maintained-
Datagrams
Portacol-
TCP, UDP
Device-
Gateway

Question 18

Network layer

Answer 18

Responsible for establishing maintaining, and terminating network connections
Dose routing and forwarding of information in the network
Information maintained-
Packet
Portacol-
IPV4/IPV6, X 25
Device-
Routers and layer three switches

Question 19

Data link layer

Answer 19

Responsible for reliability of the physical layer established at layer 1.
Create and recognize frame boundaries
Provide error control between adjacent nodes
Information maintained-
Frame
Protocol-
Token ring ethernet, slip, ppp, x.25
Device-
Switches which forward data packets based on the mqc address,
Bridges

Question 20

Physical layer

Answer 20

Concerned with transmitting raw bits over a communication channel
Information maintained-
Bit
Protocol-
Token ring ethernet, isdn, dsl, x.25
Device-
NIC, repeated, hubs

Question 21

TCP/IP (Transmission control protocol/ internet protocol)

Answer 21

Only have 4 layers,
Applications
Transport
Internet
Network access
Physical