Basic of Computer Network:
Difference between Computer Network and Internet.
Interconnection of multiple devices or host to
communicate with each other by sending/receiving data or information is called
as a computer network. These devices are called network devices. Whereas the internet is an interconnection of networks. The communication between computer devices
followed some protocols or rules defined by the reference model such as OSI or
TCP/IP.
Type of Internet or Internetwork.
1.
Extranet: An extranet is a communication network owned by
either a single or a many organization and can be accessed only with the valid
login credentials.
2.
Intranet: An intranet is a private network belonging to an
organization or its member. An intranet is highly secure and has a small number of
accessors.
Type of Computer
network:
A computer network
can be classified according to its area of operations. There is mainly four
types of a computer network. These are as follow:
1.
Local
Area Network (LAN)
A local area network is a collection of devices or
networks within a limited area such as building , office, school, or home. LAN is used for connecting two or more
computers using medium such as twisted pair, coaxial cable, etc. LAN is highly
secure and operates at a very high speed compared to other computer network
types. There are various kinds of media access control methods like a token ring,
token bus, or ethernet.
2.
Personal
Area Network (PAN)
PAN is used for connecting the computer devices for
personal use and exist within a small range i.e. less than 10 meters. The most
commonly used application of PAN is in cordless mice, keyboards, and Bluetooth systems
etc.
3.
Metropolitan
Area Network (MAN)
A metropolitan area network is a network that covers a large geographical area by the interconnection of a local area network (LAN). It covers the entire city, college campus, or a small region up to 50 km. The most widely used
protocols in MAN are RS-232, Frame relay, ATM, ISDN, etc.
4.
Wide
Area Network (WAN)
A wide area network is interconnections of MAN that is
it covers the entire state or even country. It is not limited to one location and
spreads over the large geographical areas through fiber optic cable or satellites.
We can easily differentiate
between the type of computer network with the help of the diagram given below:
Network devices: Hub, router, gateway, switch, repeater
Network devices is a device that is used to connect two or more devices together either in the same network or in a different network. A network connecting devices can be a repeater, hub, router, switch, or gateway. There may appear to be working as same but they are different in working.
Lets learn all one by one.
1. Repeater: A repeater operates at the physical layer and its function is to regenerate the signal without any modification. An important thing to be noted is that they regenerate the signal not amplify the signal.
2. Hub: A Hub connects multiple ports and transmits the signal to all connected ports. Hub cannot filter the data and allow it to transmit to all other ports. Hub can be an Active hub or Passive hub. Active hub is a hub that has its own power and can boost the signal own its own. Passive hub is a hub that doesn't have its own power and it will just forward the data.
3. Bridge: A bridge is just a repeater with the addon functionality of reading the MAC address of source and destination. It has a filtering capability. There are two types of bridge: a transparent bridge and a routing bridge. Transparent bridge simply works as a transmission medium between two devices and unaware of the bridge existing in the network. In a routing bridge, a source bridge performs the routing operation to determine the destination node.
4. Switch: A switch is a multiport bridge with a buffer to perform the error checking before forwarding the packets. A switch is an intelligent device with filtering capabilities. When a data frame arrives at the switch, it checks the error first then, it will search the MAC address of the destination in the switch table. There are four types of switches such as store and forward switch, cut-through switch, fragment-free switch, and adaptive switch.
5. Gateway: A gateway is a device to connect two networks together having different networking models. Gateway is also called as protocol converters and can operate at any network layer. It is generally more complex than a switch or router.
<<<<Continue to media access control methods >>>>
C
Posts
0 Comments