Data Communication has been categorized on the type of networks to connect the nodes and the topology to use for different purposes. We will understand what, why and hows of Networking Terminology.
In our previous post we have described the way we are going to share knowledge of Data Communication Concept | 2020. and we have learned about different Data Communication Channels. Today we are going to look at the types and topology of networking and also discuss of how, what and where to use this methods.
First, let’s get clear understanding of these terms.
What is a Computer Network?
A computer network is a group of computers that are connected to each other for the purpose of communication. A computer network allows computers to communicate with many other computers and to share resources and information, It is a combination of hardware and software which provide facility of sending and receiving of information between devices.
Basic Ingredients of a Network –
To establish connection between systems, any network needs sender, receiver, medium of communication and a protocol to follow.
Did you know? – ARPANET was the first operational computer network in the world.
First let us understand the basic ingredients –
1. Sender –
In communication process, a sender is someone or something that sends the information is audio, video, text, image format etc., to the receiver who receives and responds to the given information.
2. Receiver –
Receiver is a hardware/software system that receives the information from the sender throught internet following a networking protocol and uses the information for decision making purposes.
3. Medium of Communication –
Data is transferred in various mediums of communication, like through cables, air medium and uses certain technology to acheive this communication mode, we have shared the knowledge in our previous blog, click here to learn – Data Communication Channels.
4. Network Protocol –
For Data Communication, a similar protocol has to be followed by the networking systems to achieve this state. Network Protocols are a set of rules governing exchange of information in an easy, reliable and secure way.
TCP/IP stands for Transmission Control Protocol/Internet Protocol. TCP/IP is a set of layered protocols used for communication over the Internet. The communication model of this suite is client-server model. A computer that sends a request is the client and a computer to which the request is sent is the server.
TCP/IP has four layers −
- Application layer − Application layer protocols like HTTP and FTP are used.
- Transport layer − Data is transmitted in form of datagrams using the Transmission Control Protocol (TCP). TCP is responsible for breaking up data at the client side and then reassembling it on the server side.
- Network layer − Network layer connection is established using Internet Protocol (IP) at the network layer. Every machine connected to the Internet is assigned an address called IP address by the protocol to easily identify source and destination machines.
- Data link layer − Actual data transmission in bits occurs at the data link layer using the destination address provided by network layer.
TCP/IP is widely used in many communication networks other than the Internet.
The File Transfer Protocol (FTP) is a standard network protocol used for the transfer of computer files between a client and server on a computer network.
FTP is built on a client-server model architecture using separate control and data connections between the client and the server.
Using FTP to transfer files is helpful in these ways −
- Easily transfers files between two different networks
- Can resume file transfer sessions even if connection is dropped, if protocol is configure appropriately
- Enables collaboration between geographically separated teams
Point to Point Protocol or PPP is a data link layer protocol that enables transmission of TCP/IP traffic over serial connection.
Point-to-Point Protocol (PPP) is a Data link layer (layer 2) communications protocol between two routers directly without any host or any other networking in between. It can provide connection authentication, transmission encryption, and compression.
PPP is used over many types of physical networks, including serial cable, phone line, trunk line, cellular telephone, specialized radio links, and fiber optic links, such as SONET. Internet service providers (ISPs) have used PPP for customer dial-up access to the Internet, since IP packets cannot be transmitted over a modem line on their own without some data link protocol that can identify where the transmitted frame starts and where it ends.
PPP defines these three things −
- A framing method to clearly define end of one frame and start of another, incorporating errors detection as well.
- Link control protocol (LCP) for bringing communication lines up, authenticating and bringing them down when no longer needed.
- Network control protocol (NCP) for each network layer protocol supported by other networks.
Using PPP, home users can avail Internet connection over telephone lines.
Types of Network :
There are different types of network :
1. Local Area Network (LAN)
A local area network is a computer network covering small geographical area like a home, office, or small group of buildings such as school, or an airport. It is small in size but usually provideshigher data-transfer rates. It is suitable for small sites. Computers connected to LAN can share informaiton and share peripheral equipments. At present LAN is based on Ethernet technique.
2. Wide Area Network (WAN)
A wide area network is a computer network that covers broad area such as any network whose communication links cross metropolitan, regional, or national boundaries. WAN‘s are used to connect LANs and other types of netwroks together, so that users and other locations. WANs are often built using leased lines or switched circuit Internet.
3. Metropolitan Area Network (MAN)
A metropolitan area network is a large computer network that usually spans a city or a large campus. A MAN usually interconnects a number of local area networks and provides up-link services to wide area networks and the Internet Routers, switch and hub all toghether forms a MAN.
The configuration, or topology, of a network is key to determining its performance. Network topology is the way a network is arranged, including the physical or logical description of how links and nodes are set up to relate to each other.
There are numerous ways a network can be arranged, all with different pros and cons, and some are more useful in certain circumstances than others. Admins have a range of options when it comes to choosing a network topology, and this decision must account for the size and scale of their business, its goals, and budget.
Several tasks go into effective network topology management, including configuration management, visual mapping, and general performance monitoring. The key is to understand your objectives and requirements to create and manage the network topology in the right way for your business.
1. Mesh Topology :
Mesh topology is a type of networking where each node in the network may act as an independent router, regardles ofwhether it is connected to another network or not. It may be used for instances of high traffic conditions to provide alternate routes for transmission. It allows for continous connection and reconfiguration around broken or blocked paths by “hopping” from node to node until the destination is reached.
A mesh network whose nodes are all connected to each other is called a fully connected network. The cost of fully connected mesh network is high because of large amount of cable required and each node required intelligence. As a result, the network may typically be very reliable, as there is often more than one path between a source and a destination in the network.
2. Star Topology :
Star topology are one of the most common computer network topologies. Star Network consists of one central node which has intelligence called hub. Thus hub and other nodes and the transmission line between them form a graph with the topology of a star.
The star topology reduces the chance of network failure by connecting all of the systems to a central node. The failure of any one transmission line linking any peripheral node to the central node will result in the isolation of that peripheral node from all others, but the rest of the systems will be unaffected. If the central node fails then the whole system fails.
3. Ring Topology :
A ring topology is a network in which each node has equal amount of intelligence. The direction of data flow around the ring is usually one way. Each node connects to exactly two other nodes, forming a single continous pathway for signals through each node like a ring. Because a ring topology provides only one pathway between any two nodes, ring networks may be disrupted by the failure of a single link. A node failure or cable break might isolate every node attached to the ring.
4. Bus Network :
A bus network topology is a network in which a set of nodes are connected by a single communication line, called a bus. Bus networks are the simplest way to connect multiple nodes, but may have problems when two nodes want to transmit at the same time on the same bus. When a node wishes to transmit data to another node it must listen to the bus to see if anyone else is transmitting. If no data is on the bus then it will transmit. The node must be intelligent enough to listen to the bus and recognize their own address in order to recieve incoming data.
Jeez, that’s a lot of information in one blog, so take it slow read several times if required and follow our Data Communication Concept | 2020 series here.