Objectives of Computer Networking
Complex communication deals with the transfer of information between various computer terminals through communication links. From 1970s, the merger of the field of computer science and data communication has led to a fast-field of system opportunities. The technologies dominating the past decade revolve around information gathering processing, Storage and discretion.
Nowadays, the (data communication) communication is mostly digital due to high operating speed, reliability, miniaturization, precise data handling.
The interconnect computers do the job-instead of a single computer serving all the companies needs. This system is called “Computer networks”. Computer network means interconnected collection of autonomous computers. Inter commented computers able to exchange information. The connection can be via copper wire, fiber optics, microwaves and communication satellite.
Network Structure
Network reduces the cost, input hardware and cable installations. It consists of number of stations, set of nodes (IMP) and communications channels.
Network Stations: May be terminal, computers, telephones or other communication devices. They are also called HOST\END SYSTEMS. The hosts are connected to communication subnet or subnet. They carry messages from host and consist of switching elements and transmission lines. Transmission lines are also called CIRCUITS, CHANNELS, TRUNKS, move bits between the machines.
The switching elements are specialized computers used to connect two or more transmission lines. The purpose of the switching element is to choose outgoing line and forward the data arriving on an incoming line. All traffic to/from the host has to go via its IMP. They are also known as PACKET SWITCHING NODES, INTERMEDIATE SYSTEM OR DATA SWITCHING EXCHANGES.
Subnet is the collection of the communication lines and routers but not the host. The set of nods to which stations attached is the boundary of the communication network. The collection of routers and communication lines moves packets from source host to the destination host.
Network structure can be thought with
- Data terminal equipment (DTE).
- Data circuit terminating Equipment (DCE) concept.
Most digital data processing device have limited data transmission capacity and limited distance of data transmission. DTE is the end user machine, generally refers to (Devices) terminals and computers.
Example: Email terminal, workstation, ATM in a bank, sales terminal in a departmental store. They are not commonly connected directly to transmission medium.
DCE is used to connect the communication channel.
Example: modem. It interacts with DTE and provides an interface of DTE to communication network transmits and receive bits one at a time over the communication channel.
To specify the exact nature of interface between DTE and DCE various standards and protocols have been developed. DCEs and DTEs are connected in two ways. A high degree of cooperation is essential in DTE-DCE combination, as data and control information is to be exchanged. They can be connected in two ways
- Point to point configuration: Here only two DTE devices are in the channel
- Multidrop configuration: Here more than two devices are connected to the same communication channel.
This will provide the basic technology concepts required for understanding networking. The following are the lessons how we categorized Computer Network.