Data communication software

Data communication software /Networks

Communication software consists of programs used to establish a connection to other computers and networks. Transmission of data. Send information. Need compatible communication software to communicate properly. Are used to create a connection to another computers on the Internet. Are used to access the internet using a I using an using an ISP. Sam software sport file transfer protocol FTP is a standard used to upload and download files to and from a web server over the internet.

Types of networks 

Switched networks 

Sweet network consists of interconnected notes. Is transferred from source to destination through three days notice. Switch from notes to note so it is caste which network. Types of switched networks are as follows:

1. Circuit switching 
2. Packet switching 

Circuit switching: It creates a dedicated path between two nodes. Circuit must be available to transfer data. Circuit switching in three phases.
1. It establishes circuit and this connection is required before data transfer.
2. The second phase transfer the data.
3. 3rd phase disconnect the circuit.

Telephone Network is an example of circuit switching. first action is established between two telephones. Two persons can talk with each other full stop finally, terminated. Circuit switching is not very efficient because the entire circuit is dedicated for the duration of the connection and no other user can use it. it can data transfer while the connection is being established.


Packet switching: Packet switching network divide message into fixed and variable size packets and send them to the destination. More efficient and less expensive than circuit switching. Why most of the mote message to change networks. Network performance is increased in packet switching due to the reduce size of packet it uses three methods to send the packets.

Methods to send packets 
1. Datagram services 
IT treats each packet independently. Latest contains sender address enter sequence number in order to rebuild the message. To the same receiver main use different parts and and and the receiver may receive them in wrong sequence. Should be able to arrange the packets in proper order. Please call diagram in this method.

2. Switched virtual circuit 
It establishes a logical connection between two nodes before sending the packet. Published by a call setup request from the user. Connection is allocated for the duration of the session. What is container code to identify which was circuit used to reach the destination the path for reaching the destination is determined. Sending the packet. Circuit knows where to send the packet. It is different from dedicated part. Cricket means that the circuit is determined before data transmission.

3. Permanent virtual circuits 

It is used when two notes required continuous connection. Circuit permanently between two nodes and no call setup is required.

Difference between circuit switching and packet switching 

Circuit switching is a switching method that is used in Telephone networks. Aapa temporary circuit between source and destination. Sources are reserved in the network to meet the service. Chicken korma into a series of segments are packets. It contains the destination address and control instructions along with the message data. Andhra internet is based on packet switching., hotels use the address information eat packet to send it on an efficient path to its destination Peer gate different packets of the same message me follow different parts. Resemble when all packets of the message are received at destination. Communications protocol such as TCP IP can request a retransmission of missing packet if some packets are lost.


Message switching 

It does not require dedicated circuit. Send even if the receiver is not available undefined what is stored until the receive network. Very easy length. Accepting message, it and passing it to the receiver node is called store and forward faces. Process requires a computer at each note. Accept the message, enough buffer, destination and decides whether it should be sent to the network are not. Computer at the address of destination node to the message. State is node may cause some delay. Example of message switching network. Email and it passes through several computers before reaching the receiver.


Difference between message switching and circuit switching networks 

Message Switching

• Message switching networks good inefficiency. 
• Sentinel receiver not online simultaneous 
• Messages accepted on busy network. 
• Speed and code conversion. 
• Stores messages for in operative terminals.
• One message to several receiver. 

Circuit switching networks 

• Poor line efficiency. 
• Sender and receiver must be available simultaneous. 
• Message blocked when busy. 
• No priorities. 
• Little error recovery. 
• Difficult to do speed and code conversion. 
• If receiver in operative message not sent.