## Different Network Topologies and why we use them. Submitted by M.Talha Soomro Roll# 1127-BH-GEOG-2018 Section G1 Submitted to MR Imran

Network Topology
Network Topology refers to layout of a network. How different nodes in a network are connected to each other and how they communicate is determined by the network’s topology. Network Topology refers to the layout of a network and how different nodes in a network are connected to each other and how they communicate.
Types of Network Topology
Network Topology is the schematic description of a network arrangement, connecting various nodes(sender and receiver) through lines of connection.
________________________________________
BUS Topology
Bus topology is a network type in which every computer and network device is connected to single cable. When it has exactly two endpoints, then it is called Linear Bus topology.

Features of Bus Topology
1. It transmits data only in one direction.
2. Every device is connected to a single cable
1. It is cost effective.
2. Cable required is least compared to other network topology.
3. Used in small networks.
4. It is easy to understand.
5. Easy to expand joining two cables together.
1. Cables fails then whole network fails.
2. If network traffic is heavy or nodes are more the performance of the network decreases.
3. Cable has a limited length.
4. It is slower than the ring topology.
RING Topology
It is called ring topology because it forms a ring as each computer is connected to another computer, with the last one connected to the first. Exactly two neighbours for each device.

Features of Ring Topology
1. A number of repeaters are used for Ring topology with large number of nodes, because if someone wants to send some data to the last node in the ring topology with 100 nodes, then the data will have to pass through 99 nodes to reach the 100th node. Hence to prevent data loss repeaters are used in the network.
2. The transmission is unidirectional, but it can be made bidirectional by having 2 connections between each Network Node, it is called Dual Ring Topology.
3. In Dual Ring Topology, two ring networks are formed, and data flow is in opposite direction in them. Also, if one ring fails, the second ring can act as a backup, to keep the network up.
4. Data is transferred in a sequential manner that is bit by bit. Data transmitted, has to pass through each node of the network, till the destination node.
1. Transmitting network is not affected by high traffic or by adding more nodes, as only the nodes having tokens can transmit data.
2. Cheap to install and expand
1. Troubleshooting is difficult in ring topology.
2. Adding or deleting the computers disturbs the network activity.
3. Failure of one computer disturbs the whole network.
STAR Topology
In this type of topology all the computers are connected to a single hub through a cable. This hub is the central node and all others nodes are connected to the central node.

Features of Star Topology
1. Every node has its own dedicated connection to the hub.
2. Hub acts as a repeater for data flow.
3. Can be used with twisted pair, Optical Fibre or coaxial cable.
1. Fast performance with few nodes and low network traffic.
2. Hub can be upgraded easily.
3. Easy to troubleshoot.
4. Easy to setup and modify.
5. Only that node is affected which has failed, rest of the nodes can work smoothly.
1. Cost of installation is high.
2. Expensive to use.
3. If the hub fails then the whole network is stopped because all the nodes depend on the hub.
4. Performance is based on the hub that is it depends on its capacity
MESH Topology
It is a point-to-point connection to other nodes or devices. All the network nodes are connected to each other. Mesh has n(n-1)/2 physical channels to link n devices.
There are two techniques to transmit data over the Mesh topology, they are :
1. Routing
2. Flooding
MESH Topology: Routing
In routing, the nodes have a routing logic, as per the network requirements. Like routing logic to direct the data to reach the destination using the shortest distance. Or, routing logic which has information about the broken links, and it avoids those node etc. We can even have routing logic, to re-configure the failed nodes.
MESH Topology: Flooding
In flooding, the same data is transmitted to all the network nodes, hence no routing logic is required. The network is robust, and the its very unlikely to lose the data. But it leads to unwanted load over the network.

Types of Mesh Topology
1. Partial Mesh Topology : In this topology some of the systems are connected in the same fashion as mesh topology but some devices are only connected to two or three devices.
2. Full Mesh Topology : Each and every nodes or devices are connected to each other.
Features of Mesh Topology
1. Fully connected.
2. Robust.
3. Not flexible.
1. Each connection can carry its own data load.
2. It is robust.
3. Fault is diagnosed easily.
4. Provides security and privacy.
1. Installation and configuration is difficult.
2. Cabling cost is more.
3. Bulk wiring is required.
TREE Topology
It has a root node and all other nodes are connected to it forming a hierarchy. It is also called hierarchical topology. It should at least have three levels to the hierarchy.

Features of Tree Topology
1. Ideal if workstations are located in groups.
2. Used in Wide Area Network.
1. Extension of bus and star topologies.
2. Expansion of nodes is possible and easy.
3. Easily managed and maintained.
4. Error detection is easily done.
1. Heavily cabled.
2. Costly.
3. If more nodes are added maintenance is difficult.
4. Central hub fails, network fails.
HYBRID Topology
It is two different types of topologies which is a mixture of two or more topologies. For example if in an office in one department ring topology is used and in another star topology is used, connecting these topologies will result in Hybrid Topology (ring topology and star topology).

Features of Hybrid Topology
1. It is a combination of two or topologies
1. Reliable as Error detecting and trouble shooting is easy.
2. Effective.
3. Scalable as size can be increased easily.
4. Flexible.
1. Complex in design.
2. Costly.

## Muhammad Salman Farsi 0040-BH-ENV-18 Assignment Topic: computer generation and its type Submitted to: Sir Imran rafiq

Assignment
Roll no: 0040-BH-ENV-2018
Section: H1
Major Subject: Environmental science (SDSC)
Assignment Topic: computer generation and its Types

Submit to: sir Imran rafiq
Government College University Lahore

The five generations of computers
Computers are such an integral part of our everyday life now most people take them and what they have added to life totally for granted.
First-generation-computer Even more so the generation who have grown from infancy within the global desktop and laptop revolution since the 1980s.

The history of the computer goes back several decades however and there are five definable generations of computers
Each generation is defined by a significant technological development that changes fundamentally how computers operate – leading to more compact, less expensive, but more powerful, efficient and robust machines.

1940 – 1956: First Generation – Vacuum Tubes
These early computers used vacuum tubes as circuitry and magnetic drums for memory. As a result they were enormous, literally taking up entire rooms and costing a fortune to run. These were inefficient materials which generated a lot of heat, sucked huge electricity and subsequently generated a lot of heat which caused ongoing breakdowns.

These first generation computers relied on ‘machine language’ (which is the most basic programming language that can be understood by computers). These computers were limited to solving one problem at a time. Input was based on punched cards and paper tape. Output came out on print-outs. The two notable machines of this era were the UNIVAC and ENIAC machines – the UNIVAC is the first every commercial computer which was purchased in 1951 by a business – the US Census Bureau.
1956 – 1963: Second Generation – Transistors
The replacement of vacuum tubes by transistors saw the advent of the second generation of computing. Although first invented in 1947, transistors weren’t used significantly in computers until the end of the 1950s. They were a big improvement over the vacuum tube, despite still subjecting computers to damaging levels of heat. However they were hugely superior to the vacuum tubes, making computers smaller, faster, cheaper and less heavy on electricity use. They still relied on punched card for input/printouts. The language evolved from cryptic binary language to symbolic (‘assembly’) languages. This meant programmer could create instructions in words. About the same time high level programming languages were being developed (early versions of COBOL and FORTRAN). Transistor-driven machines were the first computers to store instructions into their memories – moving from magnetic drum to magnetic core ‘technology’. The early versions of these machines were developed for the atomic energy industry.
1964 – 1971: Third Generation – Integrated Circuits
By this phase, transistors were now being miniaturised and put on silicon chips (called semiconductors). This led to a massive increase in speed and efficiency of these machines. These were the first computers where users interacted using keyboards and monitors which interfaced with an operating system, a significant leap up from the punch cards and printouts. This enabled these machines to run several applications at once using a central program which functioned to monitor memory. AS a result of these advances which again made machines cheaper and smaller, a new mass market of users emerged during the ‘60s.
1972–2010: Fourth Generation -Microprocessors
This revolution can be summed in one word: Intel. The chip-maker developed the Intel 4004 chip in 1971, which positioned all computer components (CPU, memory, input/output controls) onto a single chip. What filled a room in the 1940s now fit in the palm of the hand. The Intel chip housed thousands of integrated circuits. The year 1981 saw the first ever computer (IBM) specifically designed for home use and 1984 saw the MacIntosh introduced by Apple. Microprocessors even moved beyond the realm of computers and into an increasing number of everyday products.The increased power of these small computers meant they could be linked, creating networks. Which ultimately led to the development, birth and rapid evolution of the Internet? Other major advances during this period have been the Graphical user interface (GUI), the mouse and more recently the astounding advances in lap-top capability and hand-held devices.
2010: Fifth Generation – Artificial Intelligence
Computer devices with artificial intelligence are still in development, but some of these technologies are beginning to emerge and be used such as voice recognition.AI is a reality made possible by using parallel processing and superconductors. Leaning to the future, computers will be radically transformed again by quantum computation, molecular and Nano technology. The essence of fifth generation will be using these technologies to ultimately create machines which can process and respond to natural language, and have capability to learn and organise themselves.

TYPES OF PROCESSOR
Intel Core i3
The Intel Core i3-7020U is a dual-core processor of the Kay Lake architecture. It offers two CPU cores clocked at 2.3 GHz (without Turbo Boost) and integrates Hyper Threading to work with up to 4 threads at once. The architectural differences are rather small compared to the Sky lake generation therefore the performance per MHz should be very similar. The Sock includes a dual channel DDR4 memory controller and Intel HD Graphics 620 graphics card (clocked at 300 – 1000 MHz). It is manufactured in an improved 14nm Fin FET process at Intel. Compare to the old i3-7100U, the newer i3-7020U is clocked 100 MHz lower (CPU cores) and therefore the current entry level model for the Core i3 line. The similar Pentium Gold 4415U offers less Cache ( 2 versus 3 MB) and a slower GPU.
Power usage varies for the Core i3 processors:
Slower speeds (1.30 GHz to 1.80 GHz) use 11.5 W, 15 W or 25 W of power Medium speeds (2.00 GHz to 2.50 GHz) use 28 W, 35 W or 37 W of power Faster speeds (2.90 GHz to 3.50 GHz) use 35 W, 37 W or 54 W of power Core i3 processors are often used in laptop computers, due to their lower heat generation and conservative battery usage. Some laptops can be used for up to five or six hours on a single battery charge when running a Core i3 processor.
Architecture
Intel basically uses the same micro architecture compared to Sky lake, so the per-MHz performance does not differ. The manufacturer only reworked the Speed Shift technology for faster dynamic adjustments of voltages and clocks, and the improved 14nm process allows much higher frequencies combined with better efficiency than before.
Cooling Requirements
All Core i3 processors require a good fan and heat sink to dissipate wasted heat energy. First- and second-generation Core i3 processors have maximum thermal design power ratings ranging from 16 to 73 watts, meaning their cooling systems must be capable of dissipating that much power in the form of heat. These modest thermal limits reflect the Core i3’s low-end status compared to the much hotter-running Core i5 and Core i7 processors, but nevertheless you may want to consider upgrading the stock cooling unit that comes with the processor. If you do, make sure it fits the CPU socket before you buy it.
CPU Socket
The socket where your central processor plugs into your main board comprises the most essential connection in your computer. All other hardware requirements follow from this pairing. The Core i3-5xx processor series uses an LGA1156 socket and the Core i3-2xxx processor series use an LGA1155 socket. If you plan to upgrade to a Core i3, even from an earlier Core i3 processor, be sure to check the socket specifications of your current processor and the one you plan to buy. If the two don’t match you will need to buy a new motherboard unless your current board supports the new socket type, which is not likely.
RAM
The Intel Core i3 processor series supports DDR3 RAM with frequencies of 1,066 or 1,333 MHz Faster RAM will be slowed down to 1,333 MHz Slower RAM won’t be able to keep up and you should upgrade it. The most common type of RAM used with a Core i3 processor is DDR3 1333 or DDR3 1600.
Specifications
Generation: 4th gen
Product Description: Dell OptiPlex 3020 – Core i3 4130 3.4 GHz – 2 GB – 500 GB
Type: Personal computer
Processor: 1 x Intel Core i3 (4th Gen) 4130 / 3.4 GHz (Dual-Core)
Processor Socket: LGA1150 Socket
Processor Main Features: Intel Turbo Boost Technology
Cache Memory: 3 MB L3 Cache
Cache per Processor: 3 MB
RAM: 2 GB (installed) / 16 GB (max) – DDR3 SDRAM – non-ECC – 1600 MHz – PC3-12800
Hard Drive, 1 x 500 GB – SATA
Optical Storage: DVD±RW
Graphics Controller: Intel HD Graphics 4600
Power: AC 120/230 V (50/60 Hz)
OS Provided: DOS
Intel Core i5
Developed and manufactured by Intel, the Core i5 is a computer processor, available as dual-core or quad-core. It can be used in both desktop and laptop computers, and is one of three types of processors in the “i” series (also called the Intel Core family of processors). The Intel Core i5-8500 is a mid-range 6-core CPU. The processor belongs to the Coffee Lake generation and was presented in April 2018. It does not support Hyper-Threading, which means it can run six threads simultaneously. The base clock rate is 3 GHz and the CPU can speed up to 4.1 GHz under high load. Despite belonging to the new generation of CPUs, the Core i5-8500 is manufactured in an improved 14nm process. The Core i5 processor is available in multiple speeds, ranging from 1.90 GHz up to 3.80 GHz, and it features 3 MB, 4 MB or 6 MB of cache. It utilizes either the LGA 1150 or LGA 1155 socket on a motherboard. Core i5 processors are most often found as quad-core, having four cores. However, a select few high-end Core i5 processors feature six cores.

Power usage varies for the Core i5 processors:
Slower speeds (1.90 GHz to 2.30 GHz) use 11.5 W of power
Medium speeds (2.60 GHz to 3.10 GHz) use 15 W, 25 W, 28 W or 37 W of power
Faster speeds (3.20 GHz to 3.80 GHz) use 35 W, 37 W, 45 W, 47 W, 65 W or 84 W of power
Core i5 processors are commonly found in desktop computers for most everyday use and some higher performance needs. Some laptop computers feature Core i5 processors as well, to provide improved performance for heavier usage needs. At the lower speeds, battery usage is pretty conservative and can reach up to five hours or usage on a single charge. However, at higher speeds, battery usage is higher and may result in up to three hours or so of usage per charge.
Ram
The most common type of RAM used with a Core i5 processor is DDR3 1333 or DDR3 1600, however, higher performance RAM can be used as well (if the motherboard supports it).
Performance
The processor offers a strong performance increase compared to the Core i5-7500 due to its two additional cores. Single-core performance has not improved significantly compared to its Kay Lake predecessor. As a mid-range model, the Core i5-8500 should be suitable for demanding games and programs.
Graphics
The integrated Intel UHD Graphics 630 input is supposed to offer higher performance as its clock rate has been increased by 50-100 MHz The build is identical to that of the Intel HD Graphics 630. We do expect a performance improvement, but as a low-end solution it will probably only display current games smoothly at reduced details – if at all.
Power Consumption
Intel specifies the TDP with 65 watts. Therefore, well-dimensioned cooling systems should easily manage to deal with the created heat. We expect increased efficiency due to the higher performance.
Specification
Processor type, Intel Core i5 8th Generation
Processor Speed, 2.1GHz
No of Cores, 6
Series Core i5 (Desktop) Coffee Lake, Intel Core i5-8600K 3600 – 4300 MHz 6 / 6 9 MB
Intel Core i5-8500 (compare) 3000 – 4100 MHz 6 / 6 9 MB
Intel Core i5-8400 (compare) 2800 – 4000 MHz 6 / 6 9 MB
Intel Core i5-8500T (compare) 2100 – 3500 MHz 6 / 6 9 MB
Clock Rate, 3000 – 4100 MHz
Level 1 Cache, 384 KB
Level 2 Caches, 1.5 MB
Level 3 Cache, 9 MB
Number of Cores / Threads, 6 / 6
Max. Temperature, 100 °C
Socket, FCLGA1151
Features, Dual-Channel DDR3 (L)-1600/DDR4-2666 Memory Controller, Hyper Threading, AVX, AVX2, AES-NI, TSX-NI, Quick Sync, Virtualization, vapor
GPU, Intel UHD Graphics 630 (350 – 1100 MHz)
Graphics memory, Intel Integrated Graphics
Intel Core i7
Intel Core i7 is a line of Intel CPUs which span eight generations of Intel chipsets. They feature either four or six cores, with stock frequencies between 2.6 and 3.7 GHz. The first i7 processors were released in November 2008.Variations of the i7 processor are manufactured for a variety of personal computing devices. Some high-performance i7 processors for desktop computers, such as the i7-8700K, are unlocked for over clocking. High-efficiency i7 processors (which conserve energy as much as possible, at the expense of some performance) are manufactured for desktop computers, laptops, and mobile devices. The i7 processor is marketed primarily to gaming enthusiasts, and digital artists such as filmmakers and animators. Intel presented its new Core i7 Quad Core processors for high-end notebooks. The three introduced CPUs should replace the mobile Quad Core processors and therefore only suited for big laptops. Technically, they are relatively low clocked desktop Core i7 CPUs with a higher built-in over-clock option. The mobile Core i7 is based on the recently introduced 45nm Desktop i5/i7 (Lynnfield) processors and is therewith the first native Quad Core CPU for notebooks (as the Core 2 Quad CPUs consist of two Core 2 Duo CPUs on one chip).
The biggest innovation is the integrated memory controller for DDR3 memory modules. Due to the direct connection the memory performance should be clearly better compared to the old Core 2 Duo / Core 2 Quad CPUs. According to Intel the performance of the memory bandwidth is more than doubled in ISOFT Sandra 2009. Another advantage of its architecture is the option to separately and dynamically switch single parts of the processor (cores, cache, I/O, memory system) on or off. Compared to the usual processor states this allows to save even more energy on low load (no leak currents in switched off parts).
CPU
I7 CPUs use relative low base clock rates (1.6-2.0 GHz), the Turbo Boost technology already introduced in the latest Core 2 Duos becomes more important. Depending on load and temperature single cores of the CPU can be clearly over clocked. E.g., if only one core is used to capacity (and the cooling system is sufficiently sized) the Core i7-820QM can be over clocked from 1.73 GHz to 3.06 GHz. Due to this automated over clocking the low clocked i7 can especially score points in old applications (e.g., older games) which only use one core. This way it can even outperform fast Core 2 Duo processors in these applications.
Performance
According to Intel’s marketing the new architecture can, compared to the Core 2 processors, achieve clear performance gains in nearly all fields of applications. Compared to the former top model, the QX9300 Quad-Core, the new results of the i7-920XM are by about 10-80% better. Because of its overclocking option this CPU can score points in single-threaded applications as well as in multi-threaded applications (new architecture). Only in extreme situations and if overclocking is not applicable, the clearly higher clocked QX9300 scores.
Limited edition i7-8086K
In June 2018, Intel announced a limited edition i7 processor, the i7-8086K, to commemorate the 40th anniversary of the 8086 CPU. Only 8086 of these processors were produced. It is the first Intel processor to reach speeds of 5 GHz without over clocking (using Intel Turbo Boost technology).
Cache Memory
In addition to generally faster base clock speeds, Core i7 processors have larger cache (on-board memory) to help the processor deal with repetitive tasks faster. If you’re editing and calculating spreadsheets, your CPU shouldn’t have to reload the framework where the numbers sit. This info will sit in the cache, so when you change a number, the calculations are almost instantaneous. Larger cache sizes help with multitasking as well, since background tasks will be ready for when you switch focus to another window. On currently available desktop processors, most i5 CPUs have up to 9MB of L3 cache, while most i7 processors have up to 12MB.
Specifications

CPU Family
7th generation Intel core “Kay lake”

Number of Cores

CPU Clock Speed
2.8-3.8GHz

Cache Size
6MB

Memory support
DDR3 1600MHz
DDR4 2133MHz
DDR4 2400MHz

Integrated Graphics
Intel HD 630

Production Technology
14-nanometer

Technologies

Intel Core i9
Intel made a big splash at Compute with its new Core i9 X-series family, with the crown jewel being its 18-core processor for desktops. But until we haven’t heard much in the way of technical details. Today, Intel revealed that the 18-core i9-7980XE will feature a base speed of 2.6GHz, with a Turbo Boost 2.0 clock of 4.2GHz. And using Turbo Boost 3.0, which speeds up performance of its fastest two cores, it’ll reach 4.4GHz.
That’s just below the 4.5GHz top speed of Intel’s Core i7-7700K, its fastest mainstream processor for desktops. Basically, that means the 18-core chip will be no slouch when it comes single-threaded performance for games. (Check out our in-depth story on the development of the 18-core processor here.) Yes, it might seem strange to see the company’s most powerful processor with a base clock speed under 3GHz. But what’s more important are the boost figures, which will kick in when you actually need more computing power. As for the other members of the X-series family, the 16-core model will feature speeds between 2.8GHz and 4.4GHz, while the 14-core version starts at 3.1GHz. As usual, Intel can reach higher speeds on chips with fewer cores since there’s less of a heat issue to worry about. It’ll be a while until we get full benchmarks from these chips, but Intel gave us a small preview from its own testing. The 16-core i9 CPU reached a Cinebench R15 score of 3,200, while running an NVIDIA GTX 1080Ti GPU. That’s below a 24-core Xeon E5 2697, according to 3D Fluff’s database. The quad-core i7-7700K, meanwhile, scored just 966 on that same benchmark. You can nab the 14- to 18-core i9 CPUs on September 25th while the 12-core version is coming sooner, on August 28th. The other chips are already available.
Intel Core i5-9600K, 6 Cores, and 6 Threads with Higher Clocks
The Intel Core i5-9600K is a 6 core and 6 thread parts with 9 MB of L3 cache. This makes it very similar to the Core i5-8600K. The difference is that it features higher clock speeds of 3.7 GHz base, 4.6 GHz boost (1 core), 4.5 GHz (2 core), 4.4 GHz (4 core) and 4.3 GHz (6 core). All of this is done at the same TDP of 95W. The main thing to note here is that the part is listed with 100 MHz higher frequencies than what was reported in Intel’s own documents which were posted a while back. Now they weren’t final in any way so changes were expected. Also, having no 6 cores and 12 thread part in the lineup is also slightly unusual but we can see Intel taking this approach as every ‘K’ SKU beneath the flagship part comes with a non-multi-threaded design. As an example, the Core i7-8700K was the only 6/12 part while the Core i5-8600K was 6/6 and Core i3-8350K was 4/4.
There’s no word on the pricing or launch date but we know that these chips are expected to be introduced in the coming months so we will keep you posted as more information arrives. Aside from that, motherboard makers have already started shipping new BIOS firmware to support the upcoming CPUs which you can check out here.
Specification
Processor: 8C, 6C, 4C (6 Consumer SKUs at Launch)
Enhanced IA and Memory Overclocking
Gen 9 Intel Graphics GT2 (Up To 24 EUs)
Consumer Only
Process Node: 22nm
Memory: Up to DDR4-2666 (Native)
Media, Display & Audio: DP 1.2 & HDMI 1.4
HDCP 2.2 (HDMI 2.0a w/LSPCON)
HEVC & VP9 10-bit End/Dec, HDR, Rec.2020, DX12
Integrated Dual-Core Audio DSP
I/O & Connectivity: Integrated USB 3.1 Gen 1 (5 Gaps)
Thunderbolt 3.0 (Alpine Ridge)
Storage: Next Gen Intel Octane memory
Pie 3.0, SATA 3.0
Security: Intel SGX 1.0

## SUBMITTED BY: MUHAMMAD USMAN ROLL NO: 0215-BH-CHEM-18(G1) TOPIC: NETWORK TOPOLOGY SUBMITTED TO: DR. IMRAN RAFIQUE GOVERNMENT COLLEGE UNIVERSITY, LAHORE

Topology:

Network topology is the arrangement of the elements of a communication network. Network topology can be used to define or describe the arrangement of various types of telecommunication networks, including command and control radio networks, industrial fieldbusses and computer networks

Types of Network Topology

Network Topology is the schematic description of a network arrangement, connecting various nodes(sender and receiver) through lines of connection.

BUS Topology

Bus topology is a network type in which every computer and network device is connected to single cable. When it has exactly two endpoints, then it is called Linear Bus topology.

Features of Bus Topology

1. It transmits data only in one direction.
2. Every device is connected to a single cable.

1. It is cost effective.
2. Cable required is least compared to other network topology.
3. Used in small networks.
4. It is easy to understand.
5. Easy to expand joining two cables together.

1. Cables fails then whole network fails.
2. If network traffic is heavy or nodes are more the performance of the network decreases.
3. Cable has a limited length.
4. It is slower than the ring topology.

RING Topology

It is called ring topology because it forms a ring as each computer is connected to another computer, with the last one connected to the first. Exactly two neighbours for each device.

Features of Ring Topology

1. A number of repeaters are used for Ring topology with large number of nodes, because if someone wants to send some data to the last node in the ring topology with 100 nodes, then the data will have to pass through 99 nodes to reach the 100th node. Hence to prevent data loss repeaters are used in the network.
2. The transmission is unidirectional, but it can be made bidirectional by having 2 connections between each Network Node, it is called Dual Ring Topology.
3. In Dual Ring Topology, two ring networks are formed, and data flow is in opposite direction in them. Also, if one ring fails, the second ring can act as a backup, to keep the network up.
4. Data is transferred in a sequential manner that is bit by bit. Data transmitted, has to pass through each node of the network, till the destination node.

1. Transmitting network is not affected by high traffic or by adding more nodes, as only the nodes having tokens can transmit data.
2. Cheap to install and expand

1. Troubleshooting is difficult in ring topology.
2. Adding or deleting the computers disturbs the network activity.
3. Failure of one computer disturbs the whole network.

STAR Topology

In this type of topology all the computers are connected to a single hub through a cable. This hub is the central node and all others nodes are connected to the central node.

Features of Star Topology

1. Every node has its own dedicated connection to the hub.
2. Hub acts as a repeater for data flow.
3. Can be used with twisted pair, Optical Fibre or coaxial cable.

1. Fast performance with few nodes and low network traffic.
2. Hub can be upgraded easily.
3. Easy to troubleshoot.
4. Easy to setup and modify.
5. Only that node is affected which has failed, rest of the nodes can work smoothly.

1. Cost of installation is high.
2. Expensive to use.
3. If the hub fails then the whole network is stopped because all the nodes depend on the hub.
4. Performance is based on the hub that is it depends on its capacity

MESH Topology

It is a point-to-point connection to other nodes or devices. All the network nodes are connected to each other. Mesh has n(n-1)/2 physical channels to link n devices.

There are two techniques to transmit data over the Mesh topology, they are :

1. Routing
2. Flooding

MESH Topology: Routing

In routing, the nodes have a routing logic, as per the network requirements. Like routing logic to direct the data to reach the destination using the shortest distance. Or, routing logic which has information about the broken links, and it avoids those node etc. We can even have routing logic, to re-configure the failed nodes.

MESH Topology: Flooding

In flooding, the same data is transmitted to all the network nodes, hence no routing logic is required. The network is robust, and the its very unlikely to lose the data. But it leads to unwanted load over the network.

Types of Mesh Topology

1. Partial Mesh Topology : In this topology some of the systems are connected in the same fashion as mesh topology but some devices are only connected to two or three devices.
2. Full Mesh Topology : Each and every nodes or devices are connected to each other.

Features of Mesh Topology

1. Fully connected.
2. robust
3. Not flexible.

1. Each connection can carry its own data load.
2. It is robust.
3. Fault is diagnosed easily.
4. Provides security and privacy.

1. Installation and configuration is difficult.
2. Cabling cost is more.
3. Bulk wiring is required.

TREE Topology

It has a root node and all other nodes are connected to it forming a hierarchy. It is also called hierarchical topology. It should at least have three levels to the hierarchy.

Features of Tree Topology

1. Ideal if workstations are located in groups.
2. Used in Wide Area Network.

1. Extension of bus and star topologies.
2. Expansion of nodes is possible and easy.
3. Easily managed and maintained.
4. Error detection is easily done.

1. Heavily cabled.
2. If more nodes are added maintenance is difficult.
3. Central hub fails, network fails.

HYBRID Topology

It is two different types of topologies which is a mixture of two or more topologies. For example if in an office in one department ring topology is used and in another star topology is used, connecting these topologies will result in Hybrid Topology (ring topology and star topology).

Features of Hybrid Topology

1. It is a combination of two or topologies

1. Reliable as Error detecting and trouble shooting is easy.
2. effective
3. Scalable as size can be increased easily.
4. flexible

1. Complex in design.
2. costly

## Topology and it’s types

NAME: USAMA NUMAN
ROLL NO: 543-BH-2018
SECTION: G1

: NETWORK TOPOLOGY AND ITS TYPES:

Network topology:
The way in which a number of computers are connected together in a network is called network topology. It is physical layout or arrangement of computer in a network.

There are five basic topology for connecting computers in a network.
1. Bus topology.
2. Star topology.
3. Ring topology.
4. Tree topology.
5. Mesh topology.

1. Bus topology:
In bus topology, the computers or network nodes are connected to a common communication medium, called the backbone.
Working of bus topology:
The sending computer attaches the address of the destination computer with the data. It then sends this data to the bus. All computers connected to the bus receive the data but only that computer accepts the data whose adders matches the address attached with the data.
In this topology only one computer can send data at a time.
Therefore, the speed of a network reduces as the number of computers attached to the bus increases.
also be used to extend th not affect the rest of the network.

bus. A cable-break, fault in any one computer or a loose connection may cause breakdown of the whole network.
2. Ring topology:
In ring topology, each computer or node is connected to the next computer and the last computer is connected to the first. Thus, a ring of computer is formed.
Working of ring topology:
Every computer receives message from the previous computer and transmits it to the next computer till the destination computer receive the message. Since each computer re-transmits what it receives, signal-loss does not occur.

network.
3. Star topology:
In star topology, all computers or nodes are directly connected to a central device. The central device that connects the nodes is called hub.
Working of star topology:
Each computer on a star network communicates with the cable hub. The hub then sends data to the destination computer.
ral
central hub and a node is relatively low, low specification twisted pair can be used to connect the nodes to the central hub.

costly.
4: tree topology:
A tree topology combines characteristics of linear bus and star topologies, it consists of groups of star configured work stations connected to a linear bus. The bus works as a backbone cable for the network.

Supported by several hardware and software manufactures.

difficult to configure and wire than other topology.
5. Mesh topology:
In mesh topology, each device is physically connected to every other device on the network. Thus messages sent on a mesh network can take
any of several possible path from source of destination. Each device is physically connected to every other device on the network. This increase performance and reliability. However the complexity and difficulty of creating a mesh network increases as a number of nodes on the network increases For example, a three or four node mesh network is relatively easy to create, where as it is impractical to set up a mesh network of 50 nodes. Mesh network are not used much in local area networks(LANs) but are used in wide area networks (WANs) where reliability is important and the number of devices being connected together is fairly small,
6 Point to point
The simplest topology is a permanent link between two endpoints. Switched point-to-point topologies are the basic model of conventional telephony. The value of a permanent point-to-point network is the value of guaranteed, or nearly so, communications between the two endpoints. The value of an on-demand point-to-point connection is proportional to the number of potential pairs of subscribers, and has been expressed as Metcalfe’s Law.
Advantages of Point to Point Topology:
1. Highest Bandwidth because there is only two nodes having entire bandwidth of a link
2. Very fast compared to other network topologies because it can access only two nodes.
3. Very simple connectivity
4. It provides low Latency
5. Easy to handle and maintain
6. Node Can be Replaced in few seconds
Disadvantages of Point to Point Topology:
1. This topology is only used for small areas where nodes are closely located.
2. The entire network depends on the common channel in case of link broken entire network will become dead.
3. There is another major drawback of this topology there are only two nodes if any of the node stops working, data cannot be transfer across the network.
Hybrid topology
A hybrid topology is a type of network topologythat uses two or more differing network topologies. These topologies include a mix of bus topology, mesh topology, ring topology, star topology, and tree topology.