1. OpenLab 1
Socket Programming
openlabworld@gmail.com

2. OpenLab 2
Socket Programming

3. OpenLab 3
TCP/IP Beginning

4. OpenLab 4
TCP/IP ModelEncapsulation Decapsulation

5. OpenLab 5
Socket Description

6. OpenLab 6
Sockets
● Defination - An interface between an
application process and transport layer
– The application process can send/receive
messages to/from another application process
(local or remote)via a socket
● Types of Sockets
– TCP/Stream Socket
– UDP/Datagram Socket
– Raw Socket
● No Sockets – No communication

7. OpenLab 7
Socket Programming
using JAVA
● I/O Stream
● Reader/Writer
● Create Socket (Class)
– TCP Socket
● Server ServerSocket
● Client Socket
– UDP Socket
● DatagramSocket

8. OpenLab 8
I/O Stream
*https://docs.oracle.com/javase/tutorial/essential/io/streams.html
OutputStream
InputStream
Write
Read
- Input Source
- Output Destination
A stream can represent
many different kinds of
sources & destinations -
- Files
- Devices
- Programs
- Memory arrays

9. OpenLab 9
Classification of Streams
● Byte Stream
– Data in the form of individual bytes
● Text Strem
– Data as character of each 2 bytes

10. OpenLab 10
Byte Strem
● Byte Stream
– Data in the form of individual bytes
● InputStrem
– DataInputStream
– FileInputStream
– BufferedInputStream
– . . .
● OutputStream
– DataOutputStream
– FileOutputStream
– BufferedOutputStream
– . . .

11. OpenLab 11
Text Stream
● Text Stream
– Data as character of each 2 bytes
● Reader
– FileReader
– BufferedReader
● Writer
– FileWriter
– BufferedWriter

12. OpenLab 12
Steps to create
Socket(Server/Client)
● TCP Server Socket
– Step-1 Create ServerSocket Object
– Step-2 Wait for the client request
– Step-3 Create I/O streams for communication to the client.
– Step-4 Perform communication with client
– Step-5 Close Socket
● TCP Client Socket
– Step-1 Create Socket Object
– Step-2 Create I/O streams for communication with the server
– Step-3 Perform I/O or communication with the server
– Step-4 Close Socket

13. OpenLab 13
Create TCP Socket
(Connection Oriented)
socket()
connect()
bind()
accept()
send()
recv()
listen()
socket()
send()
recv()
Server Client
close() close()

14. OpenLab 14
Working of TCP Socket

15. OpenLab 15
Scenario 2
● Two BEST friends , they want to chat to each
using their computer and their fathers
uninstalled messanger from their computers
Ganesh
Mohan

16. OpenLab 16
Case-1
● They decided to create a STREAM/TCP Socket
● One way Communication
I/O Stream
Client Socket
MOHAN Server Socket
GANESH
`

17. OpenLab 17
Case-2
● They decided to create a STREAM/TCP Socket
● Two way Communication
I/O Stream
Client Socket
MOHAN Server Socket
GANESH
`

18. OpenLab 18
Steps to Create UDP Socket
● UDP Server/Client
– Step-1 Create DatagramSocket object
– Step-2 Create buffer for tmp storage
– Step-3 Store/Reterive data in/from buffer
– Step-4 Create DatagramPacket
– Step-5 send/receive DatagramPacket

19. OpenLab 19
Create UDP Socket
[Connection less]
socket()
bind()
recvfrom(
)
sendto()
socket()
recvfrom(
)
sendto()
ClientServer
close() close()

20. OpenLab 20
Case-1
● They decided to create a DATAGRAM/UDP
Socket
● One way Communication
Client Socket
MOHAN Server Socket
GANESH
Datagram Packet

21. OpenLab 21
Case-2
● They decided to create a DATAGRAM/UDP
Socket
● Two way Communication
Client Socket
MOHAN Server Socket
GANESH
Datagram Packet
Datagram Packet

22. OpenLab 22
To be continued...