Connection Oriented vs Connectionless Communication

Connection Oriented vs Connectionless Communication
Connection Oriented Communication
Analogous to the telephone network.The sender requests for a communication (dial the number), the receiver gets an indication (the phone ring) the receiver accepts the connection (picks up the phone) and the sender receives the acknowledgment (the ring stops). The connection is established through a dedicated link provided for the communication. This type of communication is characterized by a high level of reliability in terms of the number and the sequence of bytes.
Connectionless Communication
Analogous to the postal service. Packets(letters) are sent at a time to a particular destination. For greater reliability, the receiver may send an acknowledgement (a receipt for the registered letters).
Based on this two types of communication, two kinds of sockets are used:
  * stream sockets: used for connection-oriented communication, when reliability in connection is desired.
  * datagram sockets: used for connectionless communication, when reliability is not as much as an issue compared to the cost of providing that reliability. For eg. streaming audio/video is always send over such sockets so as to diminish network traffic.
Sequence of System Calls for Connection Oriented communication
The typical set of system calls on both the machines in a connection-oriented setup is shown in Figure below.

The sequence of system calls that have to be made in order to setup a connection is given below.
  1. The socket system call is used to obtain a socket descriptor on both the client and the server. Both these calls need not be synchronous or related in the time at which they are called.The synopsis is given below:
 
#include<sys/types.h> |
#include<sys/socket.h> |
int socket(int domain, int type, int protocol); |
  |
  2.  
  3. Both the client and the server 'bind' to a particular port on their machines using the bind system call. This...