Computer network Topology

Hello, friends today in this part, we are discussing on computer network topology and its types.  So, here are some important points we are going to discuss

Topology is a structure or management of networking systems up to a network. Topology is practiced to define that a network is visually linked and consistent
movement of network. 

Types of computer network topology

(1) BUS topology
(2) STAR topology
(3) TREE topology
(4) MESH topology
(5) Ring topology
(6) HYBRID topology

BUS topology of computer networking

All devices are linked to a 1 backbone cable. If one device is a failure, create a problem in the entire network. In BUS topology main cable and all the devices are connected to the present main cable through drop lines.

There is a device called tap, it links the drop line to the main cable. Since all the data is transmitted over most cable, there’s a limit of drop lines and therefore the distance the most cable can have.

Advantages of Bus topology

(1) Easy to install, each cable needs to be connected with the backbone cable.
(2) Fewer cables are required than mesh and star topology.

Disadvantages of BUS topology

(1) Difficulty in fault detection.
(2) Not scalable as there’s a limit of what percentage nodes you’ll connect with backbone cable.

Star topology of computer networking

Star topology does not allow direct communication between devices, a device must have to communicate through the hub.

If one device wants to send data to a the different device, it has to first send the data to the hub and then the hub transmits that data to the designated device. Best topology ever for networking multiple devices over a network.

Advantages of Star topology

(1) Low cost because each device only needs one I/O port and needs to be connected with HUB with one link.
(2) Easy to install
(3) Less amount of cables required because each device needs to be connected with the hub only.
(4) If one link fails, other links will start working.
(5) Easy to detect fault because the link can be easily identified.

Disadvantages of star topology

(1) If the hub reduces all performance falls off, none of the systems might function beyond a hub.
(2) Hub requires higher assets and continuous actions as it is the central structure of star topology.

Tree topology of computer networking

It is the combination bus and star topology and also it has the feature of both.

Mesh-topology computer networking

In a mesh , each device is connected to each other device on the network through a fanatical point-to-point link. When we say dedicated it means the link only carries data for the 2 connected devices only.

Advantages of mesh topology

(1) No data traffic issues as there’s a fanatical link between two devices which suggests the link is merely available for those two devices.
(2) It is trustworthy and booming as a decline of one link doesn’t trouble other links and the connection among other systems on the network.
(3) There is a point-to-point link thus unauthorized communication is not possible. So Mesh is a safety procedure.
(4) It Detects faults easily.

Disadvantages of mesh topology

(1) A large amount of wires required to connect to each system is hard work.
(2) All systems require to be linked along with the next devices, the number of I/O ports needed must be huge.
(3) It displays expansibility problems as a system may not be communicated along with a huge number of systems with a committed point-to-point link.

Hybrid topology computer networking

A hybrid topology is a connection of two or more topology’s with each other.

Advantages of Hybrid topology

(1) We can choose the topology based on the requirement, for example, flexibility is our matter then we may practice star topology alteration of bus topology.
(2) Scalable as we will further connect other computer networks with the prevailing networks with different topologies.

Disadvantages of Hybrid topology

(1) Hard to identify threats.
(2) It is simple to set up.
(3) Design is complex so maintenance cost is high.

Ring topology of computer networking

In this topology, every system is linked with both systems on either side of it. There are two committed point-to-point links a system has among the devices on the other side of it. This system creates a ring so it is defined as a ring topology.

If a system needs to transfer information to another system then it delivers the information in a single order, every system in ring topology has a repeater, if the accepted information is intended for an additional device then the repeater forwards this data until the intended device receives it.

Advantages of ring topology

(1) It is simple to insert.
(2) Managing is simpler on add or remove a tool from the topology only two links are required to be changed.

Disadvantages of ring topology

(1) A link failure can fail the whole network because the signal won’t travel forward thanks to failure.
(2) Data traffic issues since all the data are circulating in a ring.

Dual RING topology of computer networking

Network devices are connected with a close loop using dual ring technology. It consists of two independent primary and secondary rings. In this topology, two rings  allow data to be sent in both directions. If one ring connection fails, data can be transmitted on the opposite ring. The Secondary ring is consonant, used only when primary rings stop functioning.

Advantages of dual ring Topology

(1) Speed and reliability

(2) Uninterrupted long distance communication

(3) Terminators are not required

How to choose Topology

Money– The BUS network may be the least expensive way to install a network.
Length– Length of cable required, the linear Bus network uses shorter lengths of cable.
Future growth– Future growth with a star topology, expanding is easily done by adding another.
Cable type– Twisted pair cable is highly practiced in business management. It sometimes practiced along with star topologies.

OSI model of Computer Network topology

OSI stands for open system interconnection. It is used to know the flow of data from a point to b point. And OSI model was progressed by the international organization for standardization (ISO) in 1984.

It is now treated as a constructive design for inter-computer connections.OSI is a logical definition for layered communications and computer network protocol models. In its highest elementary system, it partitions items into seven layers fully.

7 types of OSI model

(1) Application   (2) Presentation   (3) Session   (4) Transport   (5) Network   (6) Data link layer   (7) Physical layer

Application layer

This layer is a consideration layer that defines the common connections protocols and interface methods practiced by hosts in a connections network.

This layer consideration is practiced in two of the standard models of computer network the Internet Protocol Suite(TCP/IP) and the OSI model.

Features of application layer

(1) Network virtual terminal (software)
(2) File transfer, access, and management.
(3) Mail services
(4) Directory services- It connects to shared database authorities for whole universe data about large articles and services.

Presentation layer

The presentation layer is responsible for the formatting and delivery of information to the application layer for further processing or display.

Features of the presentation layer

(1) Translation– Interoperability among encoding devices.
(2) Encryption– Privacy policy schemes.
(3) Compression– Data compression.

Session layer

Session layer protocol is performed to review the term and discussion among the ultimate-consumer. The discussion layer brings the system for opening, closing and controlling the discussion among end-user application procedures.

In case of a network failure, this protocol should effort to get back the network. If a network isn’t performed for a long period, this layered protocol should cancel it and re-connect the network.

Features of the session layer

(1) Dialog Control– Half duplex/ Full duplex.
(2) Synchronization– Synchronization points, procedures within the common page.

Transport layer

Transport layer protocol is showing the transmission process and information. Used two protocols to carry the info/packets. The best-known transport protocol of the internet protocol suite is the transmission control protocol(TCP).

This layer is practiced for communication-related transfers, which the communications Utilizer datagram protocol(UDP) Is practiced for simpler messaging transmissions.

TCP is that the more complex protocol, because incorporating reliable transmission and data stream services. Both TCP and UDP comprise essentially all traffic on the internet and are the only protocols used in all major operating systems.

Services that the transport layer provides

Connection-oriented communication– The defect of this process is that for every delivered message, there is a condition for acceptance, including detectable network fix related to self-error-correcting packets.

The repeated requests cause a significant slowdown of network speed when defective byte streams or datagrams are sent.

Same order delivery – Ensure that packets are always delivered in strict sequence by assigning them a number.

Data integrity– Using checksums, the info integrity across all the delivery layers is often ensured. These checksums guarantee that the data transmitted is similar as the data received and which is not infected. lost or infected files may be retransferred through demanding to retransfer from other layers.

Flow control– Flow control ensures that the data is sent at a rate that is acceptable for both sides by handling data flow.

Traffic control– Digital connections networks are title to high frequency and accessing speed limitations, that may determine a huge amount of capacities for file excess on the network.

Multiplexing– This multiplexing allows the use of simultaneous applications over a network such as when different internet browsers are opened on the same computer.

Computer Network layer

Network layer makes available options about host and network addressing, managing sub-networks, and internetworking.

Functions of network layer

(1) Transmitting systems and networks.
(2) Occupying and tracking tables or static routes. Authority to target communication among networks.
(3) Connecting incoming and outgoing information and then promoting them allowing them to aspect or perform restraint position for those pockets.
(4) Internetworking between two different subnets.
(5) Delivering packets to a destination with best efforts.
(6) Provides connection-oriented and connectionless mechanisms.

Data-link layer

The data link layer is responsible for MAC addressing and LLC control checking. It is responsible for converting data streams to signals bit by bit and sending that over to the underlying hardware.

At the target point, the data link layer picks up information from the structure that is in the form of electrical signals, attach them to a detectable structure, and transfers them to the upper layer.

Datalink layer has two sub-layers
(1) Logical link control- Flow control, and error control.
(2) Media access control- Physical address or permanent address for media control.

The functionality of the data link layer

(1) Framing- Stream of bits into manageable data units.
(2) Physical Addressing- MAC address
(3) Flow control – Mechanism for overwhelming the receiver.
(4) Error control- Trailer, retransmission
(5) Multi-access control – Defining master device in the same link.
(6) Synchronization

Physical layer

It controls the visible integration among networking devices. The primary operation of the physical layer is to transfer information in the structure of electromagnetic signals across a transmission form. It’s important for the transmissions of specific bits from one hop(node) to another.

The two information and the signals can be either analog or digital. Transmission media perform by regulating efficiency onward a physical path that might be wired or wireless.

It describes the hardware components, cabling, wiring, frequencies, pulses used to represent binary signals, etc.

Characteristics of physical layer

(1) Physical characteristics of inter and medium – Transmission medium.
(2) Representation of bits- Stream of bits(0s or 1s) with no clarification and assessed with signals.
(3) Data rate- During of a bit, is how long it lasts.
(4) Synchronization of bits- The sender or receiver’s clock must be synchronized.
(5) Line configuration- Point-to-point, point-to-multipoint.
(6) All data or topology are managed in physical topology.
(7) Transmission mode- Simplex, half-duplex, full-duplex.

TCP/IP Model of Computer Networking

TCP/IP model clarify the movement of data between the source and destination or the internet. They also offer simple naming and addressing schemes.

Advantages of TCP/IP

(1) Supports to create communication between various kinds of systems.
(2) It operates independently of the operating system.
(3) It supports various routing protocols.
(4) It enables internetworking between the organizations.
(5) TCP/IP model has a highly scalable client-server architecture.
(6) It can be operated independently.
(7) Supports several routing protocols.
(8) It can be used to establish a connection between two computers.

Difference between OSI Model and TCP/IP Model

OSI Model

TCP/IP Model

(1) It is developed by ISO(International Standard Organization).
(2) OSI model provides a clear distinction between interfaces, services, and protocols.
(3) OSI indicates Open System Interconnection.
(4) OSI uses the network layer to define routing standards and protocols.
(5) OSI follows a vertical approach.
(6) OSI layers have seven layers.
(7) In the OSI model, the transport layer is only connection-oriented.
(8) The information link layer and physical are separate layers in the OSI model.
(9) Session and presentation layers are a unit of the OSI model.
(10) It is described later the arrival of the network.
(11) The minimum size of the OSI header is 5 bytes.

(1) It is developed by ARPAN(Advanced Research Project Agency Network).
(2) TCP/IP might not accept single fair differentiating marks within services, interfaces, and protocols.
(3) TCP refers to Transmission Control Protocol.
(4) TCP/IP uses only the internet layer.
(5) TCP/IP follows a horizontal approach.
(6) TCP/IP has four layers.
(7) A layer of the TCP/IP system both are content-determined and contactless.
(8) In TCP, physical and data links are two connected like a single host-to-network layer.
(9) There is no session and presentation layer in the TCP model.
(10) It is defined before the advent of the internet.
(11) The lower range header is 20 bytes.

So, friends in this part we have discussed some important points on computer network Topology, its types, advantages and disadvantages, OSI model and layers, TCP/IP and differences, etc. In the next  part-3 we will discuss what is the fiber optic cable?, Transmission mode and its types, advantages, and disadvantages, cables, connectors, wired and wireless media, etc. If you like this tutorial please like, comment, and share.

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