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. 

Advantages of Bus Topology

  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.

Disadvantages of Bus Topology

  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.

Advantages of Ring Topology

  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

Disadvantages of Ring Topology

  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.

Advantages of Star Topology

  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.

Disadvantages of Star Topology

  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.

Advantages of Mesh Topology

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

Disadvantages of Mesh Topology

  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.

Advantages of Tree Topology

  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.

Disadvantages of Tree Topology

  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
  2. Inherits the advantages and disadvantages of the topologies included

Advantages of Hybrid Topology

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

Disadvantages of Hybrid Topology

  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.
Disadvantages:

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.
Advantages:

Disadvantages:

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.
Advantages:
ral
central hub and a node is relatively low, low specification twisted pair can be used to connect the nodes to the central hub.
Disadvantages:

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.
Advantages

1) Reliable : Unlike other networks, fault detection and troubleshooting is easy in this type of topology. The part in which fault is detected can be isolated from the rest of network and required corrective measures can be taken, WITHOUT affecting the functioning of rest of the network.
2) Scalable: Its easy to increase the size of network by adding new components, without disturbing existing architecture.
3) Flexible: Hybrid Network can be designed according to the requirements of the organization and by optimizing the available resources
Disadvantages

1) Complexity of Design: One of the biggest drawback of hybrid topology is its design. Its not easy to design this type of architecture and its a tough job for designers. Configuration and installation process needs to be very efficient. 2) Costly Hub: The hubs used to connect two distinct networks, are very expensive. These hubs are different from usual hubs as they need to be intelligent enough to work with different architectures and should be function even if a part of network is down.
3) Costly Infrastructure: As hybrid architectures are usually larger in scale, they require a lot of cables, cooling systems, sophisticate network devices, etc.

Name: Syed M Haseeb Tahir Roll no: 607-BH-MB-2018(G1) Topic: Network topology & its types Submitted to: Sir Imran Rafique

Network topology 

 

Abstract: The geometrical arrangement of computer resources, remote devices and communication facilities is known as Network structure or Network topology.

 

A computer network is comprised of nodes and links, a node is the end point of any branch in a computer, a terminal device, workstation or interconnecting equipment facility.

A link is a communication path between two nodes. The terms “circuit” and “Channel” are frequently used as synonyms for the link.

There are different types of the topologies like bus, ring, tree, mesh etc. However, we will consider five basic network structures- topology.

Introduction:

Network Topology is the study of the arrangement or mapping of the elements (links, nodes, etc.) of a network interconnection between the nodes.

Topologies can be physical or logical.

Physical Topology means the physical design of a network including the devices, location and cable installation.

Logical Topology refers to the fact that how data actually transfers in a network as opposed to its design.

Some of the most common network topologies are:

  • Bus topology
  • Ring topology
  • Star topology
  • Mesh topology
  • Tree toology

 

Bus Topology

This structure is very popular for local area networks. In this structure or topology, a single network cable runs in the building or campus and all nodes are linked along with this communication line with two endpoints called the bus or backbone as show figure.

Image result for bus topology diagram

By this type of topology, if one node goes faulty all nodes may be affected as all nodes share the same cable for the sending and receiving of information. The cabling cost of bus systems is the least of all the different topologies. Each end of the cable is terminated using a special terminator.

 

 

[A]. Advantages:

  • Reliable in very small networks as well as easy to use and understand.
  • Requires least amount of cable to connect the computers (nodes) together and therefore is less expensive than other cabling arrangements.
  • It’s easy to extend, Two cables can be easily joined with a connector, making a longer cable for more computers to join the network.
  • A repeater can also be used to extend a bus configuration.

[B]. Disadvantages:

  • Heavy network traffic can slow a bus considerably because any computer can transmit at any time. But networks do not Coordinate when information is sent. Computer interrupting each other can use a lot of bandwidth.
  • Each connection between two cables weakens the electrical signal
  • The bus configuration can be difficult to find and can cause the whole networks to stop functioning.

 Ring Topology

This is yet another structure for local area networks. In this topology, the network cable passes from one node to another until all nodes are connected in the form of a loop or ring. There is a direct point-to-point link between two neighboring nodes (the Next and the Previous). These links are unidirectional which ensures that transmission by a node traverses the whole ring and comes back to the node, which made the transmission

Image result for ring topology diagram

 

Information travels around the ring from one node to the next. Each packet of data sent to the rink is prefixed by the address of the station to which it is being sent. When a packet of data arrives, the node checks to see if the packet address is the same as its own, if it is, it grabs the data in the packet. If the packet does not belong to it, it sends the packet to the next node in the ring.

Faulty nodes can be isolated from the ring. When the workstation is powered on, it connects itself to the ring. When power is off, it disconnects itself from the ring and allows the information to bypass the node.

The most common implementation of this topology is token ring. A break in the ring causes the entire network to fail. Individual nodes can be isolated from the ring.

 

[A]. Advantages:

  • Ring networks offer high performance for a small number of workstations or for larger networks where each station has a similar workload.
  • Ring networks can span longer distances than other types of networks.
  • Ring networks are easily extendable.
  • Unlike Bus topology, there is no signal loss in Ring topology because the tokens are data packets that are re-generated at each node.

 

[B]. Disadvantages:

  • Relatively expensive and difficult to install
  • Failure of one computer on the network can affect the whole network.
  • It is difficult to find fault in a ring network.
  • Adding or removing computers can disrupt the network.
  • It is much slower than an Ethernet network under normal load.

 

Star Topology

Star topology uses a central hub through which, all components are connected. In a Star topology, the central hub is the host computer, and at the end of each connection is a terminal

Image result for star topology diagram

 

 

Nodes communicate across the network by passing data through the hub. A star network uses a significant amount of cable as each terminal is wired back to the central hub, even if two terminals are side by side but several hundred meters away from the host. The central hub makes all routing decisions, and all other workstations can be simple.

An advantage of the star topology is that failure, in one of the terminals does not affect any other terminal; however, failure of the central hub affects all terminals. This type of topology is frequently used to connect terminals to a large time-sharing host computer.

[A]. Advantages:

  • It is more reliable (if one connection fails, it does not affect others)
  • The center of a star network is a good place to diagnose network faults and if one computer fails whole network is not disturbed. Hub detects the fault and isolates the faulty computer.
  • It is easy to replace, install or remove hosts or other devices, the problem can be easily detected-It is easier to modify or add a new computer without disturbing the rest of the network by simply running a new line from the computer to the central location and plugging it to the hub.
  • Use of multiple cable types in a same network with a hub.
  • It has good performance

[B]. Disadvantages

  • It is expensive to install as it requires more cable, it costs more to cable a star network because all network cables must be pulled to one central point, requiring more cable length than other networking topologies.
  • Central node dependency, if central hub fails, the whole network fails to operate.
  • Many star networks require a device at the central point to rebroadcast or switch the network traffic.

Mesh Topology

Devices are connected with many redundant interconnections between network nodes. In a well-connected topology, every node has a connection to every other node in the network. The cable requirements are high, but there are redundant paths built in.

Failure in one of the computers does not cause the network to break down, as they have alternative paths to other computers.

Image result for mesh topology diagram

 

Mesh topologies are used in critical connection of host computers (typically telephone exchanges). Alternate paths allow each computer to balance the load to other computer systems in the network by using more than one of the connection paths available.

A fully connected mesh network therefore has no (n-1) /2 physical channels to link n devices. To accommodate these, every device on the network must have (n-1) input/output ports.

 

[A]. Advantages

  • Yield the greatest amount of redundancy in the event that one of the nodes fails where network traffic can be redirected to another node.
  • Point-to-point link makes fault isolation easy.
  • Privacy between computers is maintained as messages travel along dedicated path.
  • Network problems are easier to diagnose.

[B]. Disadvantages

  • The amount of cabling required is high.
  • A large number of I/O (input/output) ports are required.

Tree Topology

The most common structure or topology known as Tree topology, Tree topology is a LAN topology in which only one route exists between any two nodes on the network. The pattern of connection resembles a tree in which all branches spring from one root.

Image result for tree topology diagram

 

Tree topology is a hybrid topology, it is similar to the star topology but the nodes are connected to the secondary hub, which in turn is connected to the central hub. In this topology group of star-configured networks are connected to a linear bus backbone.

[A]. Advantages

  • Installation and configuration of network are easy.
  • The addition of the secondary hub allows more devices to be attached to the central hub.
  • Less expensive when compared to mesh topology.
  • Faults in the network can be detected traces.

[B]. Disadvantages

  • Failure in the central hub brings the entire network to a halt.
  • More cabling is required when compared to the bus topology because each node is connected to the central hub.

Conclusion

In this paper we have to study the different types of the topologies like Bus Topology, Ring Topology, Star Topology, Mesh Topology and Tree Topology.

In this paper we have considered above five topology uses and its merits and demerits that will study will help to know that which structure or topology is best for which organization or business. We have to study the topology and finally we have to find the fact that all topologies are alternate options for business like that Bus Topology is use full for small network but its some demerits so its alternate option is Ring Topology. So finally, we can say that all topologies have some extra and different feature are available from other topology and that features are making it special from other topology.

References

 

Books: 

  1. Forouzan, Data Communication and Networking 5th Edition, Tata McGraw-Hill.
  2. Abraham Silberschatz, Henry F. Korth, S. Sudarshan – Database System Concept 6th Edition, Tata McGraw- Hill Education.
  3. Duglass Comer: Internet & Introduction Prentice
  4. Andrews Tananbaum: Computers Networks, PHI
  5. Michel and Miller: Introduction to Digital Data Communication
  6. James Martin: Telecommunication and Compute

Web sites:

  1. http://grail.cba.csuohio.edu/~sanchita/network.ppt
  2. Network Topology [On-Line] Available at. http://en.wikipedia.org
  3. http://www.sis.pitt.edu/~icucart/networking_basics/networking_topology.html

Name: Syed M Haseeb Tahir Roll no: 607-BH-MB-2018(G1) Topic: Network topology & its types Submitted to: Sir Imran Rafique

Name: Waqas Naseem Roll no: 0007-BH-BIOT-2018 Submitted to: Sir Imran Topic: Network topology and its type Government college university, Lahore

Network Topology

Definition: Network typologies describe the ways in which the elements of a network are mapped. They describe the physical and logical arrangement of the network nodes.

Physical: actual layout of the computer cables and other network devices

Logical: the way in which the network appears to the devices that use it. Different Types of Topologies:

  • Bus Topology
  • Star Topology
  • Ring Topology
  • Tree Topology

Bus Topology:

Bus topology is a specific kind of network topology in which all of the various devices in the network are connected to a single cable or line. In general, the term refers to how various devices are set up in a network.

  • Bus consists of a single linear cable called a trunk.
  • Data is sent to all computers on the trunk. Each computer examines EVERY

Packet on the wire to determine who the packet is for and accepts only

Messages addressed to them.

  • Bus is a passive topology.
  • Performance degrades as more computers are added to the bus.
  • Signal bounce is eliminated by a terminator at each end of the bus.
  • Barrel connectors can be used to lengthen cable.
  • Repeaters can be used to regenerate signals.
  • Usually uses Thinnest or Thickset
  • Both of these require 50 ohm terminator
  • Good for a temporary, small (fewer than 10 people) network
  • But it’s difficult to isolate malfunctions and if the backbone goes down, the

Entire network goes down

  • Terminators should be applied to both ends of the longest path
  • Nodes connected to the bus cable by drop lines and taps
  1. Drop lines – connection between a node and the main cable
  2. Taps – connector either splices into the main cable or punctures the

Sheathing of a cable to create a contact with the metallic core.

ADVANTAGES OF BUS TOPOLOGY:

  1. Manageable
    it is very easy to identify problems and fix them quickly and efficiently using bus topology. This is because everything is connected together.
  2. Inexpensive
    the equipment and cables that are needed to set up this form of network are very minimal. This makes it one of, if not the most, cost efficient way to set up a network of computers and servers.
  3. Cable length require
    the cable length that is needed to successfully set up a bus topology network is very small. This is because of the way that the different components are connected.
  4. Most Commonly Used
    Due to its simplicity, easy manageability, and low costs this is the most used network in businesses and technology centers all over the world. However, it works best for small networks of systems.

DISADVANTAGES OF BUS TOPOLOGY:

  1. There is limit
    the amount of systems you can connect to a bus network is limited. You can only connect as many components as you have nodes to connect them to. Once you run out of spots to connect, you either have to replace the entire bus cable or use a different networking system.
  2. Small Problems are big
    Since everything is centrally connected, if there is an issue anywhere in the cable, all of the systems connected are affected. This can cause major problems in productivity.
  3. Difficult to Locate Problems
    Since every system will be affected by a problem, it can be difficult to identify exactly where the problem is coming from and what is causing it. You have to explore every computer and connection to find the cause of the disturbance.
  4. Less Efficient
    Many computers being connected to the same connection can run into one big problem, speed. The power and bandwidth of the central cable is shared with all of the systems. These bus cables can only support so much data, and once this limit is reached, the systems attached will begin running much slower.
  5. Low security
    Due to the simplicity of this network, security breaches are very possible. Bus topology is well understood, and there is an abundance of information available on it, making it very easy to penetrate.

Choosing a network set up that fits your specific needs can be difficult and confusing. Learning about all of your options before making a decision is the smartest route to take.

Star topology:

In this configuration, every node connects to a central network device, like a hub, switch, or computer. The central network device acts as a server and the peripheral devices act as clients. Depending on the type of network card used in each computer of the star topology, a coaxial cable or an RJ-45 network cable is used to connect computers together.

  • All computers/devices connect to a central

Device called hub or switch.

  • Each device requires a single cable
  • Point-to-point connection between the Device and hub
  • Most widely implemented
  • Hub is the single point of failure.

Advantages of star topology:

1. Star Network Topology Supports Easy Installation and maintenance

It is easy to maintain network. That is why it is so popular.

2. Star Topology Supports Adding or removing computers easily

Adding or removing computers can be done without disturbing the network. We connect the new computer with the HUB by means of a networking cable. One end of the cable (RJ 45 connector) is inserted in computer’s Network Interface Card and the other end (RJ 45 connector) is plugged into the HUB, and that’s it.

3. Star Topology for Easy Fault Diagnosis

In a star network topology, finding faults is easy. If a computer is no more connected with your network, you can check its cable and connectors or network settings in its Operating system.

4. Star Network Topology Supports Network Reliability

Single computer failure will not disturb whole network, since all other computers are connected with separate links (wires) to HUB. Definitely, they will work fine. Therefore, only the faulty computer will not be able to communicate with other computers in the Local Area Network.

5. Star Network Topology for Better performance

Star topology can prevents the passing of data through an excessive number of nodes. By using a Switch, at most, 3 devices and 2 links are involved in any communication between any two devices.
6. Device Isolation
Each device is separately connected to HUB or Switch and is isolated. This is why each device works independently.

Disadvantages of star topology:

  1. High cost

They May have a higher cost to implement, especially when using a switch or router as the central network device.

 

 

 

  1. Central network

The central network device determines the performance and number of nodes the network can handle.

  1. All network disconnection

If the central computer, hub, or switch fails, the entire network goes down and all computers are disconnected from the network.

Ring topology:

Ring topology, also known as Ring network, is a type of network topology where each node is exactly connected to two other nodes, forward and backward, thus forming a single continuous path for signal transmission.

  • Each computer is connected to the

Network in a closed loop or ring

  • Each machine or computer has a unique

Address that is used for identification

Purposes

  • The signal passes through each machine

Or computer connected to the ring in one

Direction.

Advantages of ring topology:

  1. Equal access

Equal access to the resources.

  1. Point-to-point

Point to point line configuration makes it easy to identify and isolate faults.

  1. Comparison with bus topology

Performs better than a bus topology under heavy network load.

  1. Impact on bandwidth

Adding additional nodes has very little impact on bandwidth.

  1. Manage node

Does not require a central node or server to connectivity or manage nodes.

Disadvantages of ring topology:

  1. Troubleshooting

Troubleshooting is difficult in ring topology.

  1. Effect on network

Moving, adding and changing the devices can affect the network.

  1. Accidental break of cable

If any cable or link breaks, then whole network will goes down.

  1. Difficulty in adding or removing

Difficult to add and remove devices once the network has been set up.

  1. Malfunctioning workstation

One malfunctioning work station can create problems for the entire network.

 

 

Tree topology:

 

A tree topology is a type of network topology that includes at least three specific levels in a topology hierarchy. Tree typologies are valued for their scalability and accessibility for troubleshooting.

  • the most common typologies found in large

Corporations today

  • Often mirrors corporate structure
  • Use Polling

 

 

 

Advantages of Tree Network Topology:

  1. Hardware and software support

Many software and hardware vendors support tree topology.
2. Point to point writing

It provides point-to-point wiring for individual groups.

Disadvantages of Tree Network Topology:

  1. line breakage

If the main backbone line breaks, the entire tree network goes down.
2. Configuration

A tree network is more difficult to configure and maintain.
3. Hub fail

If any hub fails, related segment will be removed from the network.

 

 

 

 

 

References:

Books:

  1. Forouzan, Data Communication and Networking 5th Edition, Tata McGraw-Hill.
  2. Abraham Silberschatz, Henry F. Korth, S. Sudarshan – Database System Concept 6th Edition, Tata McGrawHill Education.
  3. Douglass Comer: Internet & Introduction Prentice
  4. Andrews Tananbaum: Computers Networks, PHI
  5. Michel and Miller: Introduction to Digital Data Communication
  6. James Martin: Telecommunication and Compute

Web sites:

  1. HTTP://grail.cba.csuohio.edu/~sanchita/network.ppt
  2. Network Topology [On-Line] Available at. HTTP://Wikipedia
  3. HTTP://www.sis.pitt.edu/~icucart/networking_basics/networking_topology.html

My First Post

It is my post at Government College University Lahore.

I have attached CV. In computer practical Lab. we have completed Microsoft Word,Microsoft Excel and PowerPoint.

A few years ago, choosing a processor was pretty straightforward. AMD and Intel each produced two series of processors, a mainstream line and a budget line. Each company used only one processor socket, and there was a limited range of processor speeds available. If you wanted an Intel processor, you might have a dozen mainstream models and a half-dozen budget models to choose among. The same was true of AMD.

Nowadays, choosing a processor isn’t as simple. AMD and Intel now make literally scores of different processor models. Each company now offers several lines of processors, which differ in clock speed, L2 cache, socket type, host-bus speed, special features supported, and other characteristics. Even the model names are confusing. AMD, for example, has offered at least five different processor models under the same name Athlon 64 3200+. An Intel Celeron model number that ends in J fits Socket 775, and the same model number without the J designates the same processor for Socket 478. A Pentium 4 processor model number that ends in J says nothing about the socket type it is designed for, but indicates that the processor supports the execute-disable bit feature. And so on.

AMD and Intel each offer the three categories of processors described in the following sections.

Budget processors give up a bit of performance in exchange for a lower price. At any given time, AMD or Intel’s fastest available budget processor is likely to have about 85% of the performance of their slowest mainstream model. Budget processors are more than sufficient for routine computing tasks. (After all, today’s budget processor was yesterday’s mainstream processor and last week’s performance processor.) Budget processors are often the best choice for a system upgrade, because their lower clock speeds and power consumption make it more likely that they’ll be compatible with an older motherboard.

The various models of the AMD Sempron processor sell in the $50 to $125 range, and are targeted at the budget through low-end mainstream segment. The Sempron replaced the discontinued Socket A Duron processor in 2004, and the obsolescent Socket A Athlon XP processor in 2005. Various Sempron models are available in the obsolescent Socket A and in the same Socket 754 used by some Athlon 64 models.

AMD actually packages two different processors under the Sempron name. A Socket A Sempron, also called a K7 Sempron, is in fact a re-badged Athlon XP processor. A Socket 754 Sempron, shown in Figure 5-1 is also called a K8 Sempron, and is really a cut-down Athlon 64 model running at a lower clock speed with a smaller L2 cache and a single-channel memory controller rather than the dual-channel memory controller of the Athlon 64. Early Sempron models had no support for 64-bit processing. Recent Sempron models include 64-bit support, although the practicality of running 64bit software on a Sempron is questionable. Still, like the Athlon 64, the Sempron also runs 32-bit software very efficiently, so you can think of the 64-bit support as future-proofing.

SUBMIITED TO : MR. IMARN RAFIQUE

SUBMITTED BY: BABAR ALI

Roll No. 1337-BH-PHIL

SECTION: E2(P6)

GOVT. COLLEGE UNIVERSITY LAHORE.

 

Advancement in computer processor

Intel Core i3

Developed and manufactured by Intel, the Core i3 is a dual-core computer processor, available for use in both desktop and laptop computers. It is one of three types of processors in the “i” series (also called the Intel Core family of processors).
The Core i3 processor is available in multiple speeds, ranging from 1.30 GHz up to 3.50 GHz, and features either 3 MB or 4 MB of cache. It utilizes either the LGA 1150 or LGA 1155 socket on a motherboard. Core i3 processors are most often found as dual-core, having two cores. However, a select few high-end Core i3 processors are quad-core, featuring four cores.
The most common type of RAM used with a Core i3 processor is DDR3 1333 or DDR3 1600.
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
Skylake, 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.

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 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.
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).
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.

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 Kaby 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 iGPU 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.

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 overclocking. 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.

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.

Intel Core i9
A family of 64-bit x86 CPUs with up to 18 cores from Intel. Introduced in 2017, the Core i9 became the top model in the Core “i” series. Also part of the Intel Core X-series brand, the first i9 CPU (7900x) is based on 14 nm process technology and the Skylake-X microarchitecture. It features four channels of DDR4 RAM and 44 lanes of PCI Express (compared with 28 in the i7). Designed for high-performance computing and gaming, the 3.3 GHz i9 chip can be overclocked to 4.5 GHz.

 

Name : Sarfraz khan

Roll no :0416-BH-Env-18

Submitted to : Imran rafique

Submitted by : Sarfraz khan

Section :H1

Types of network topologies and their use

What is a Topology?
The physical topology of a network refers to the configuration of cables, computers, and other peripherals. Physical topology should not be confused with logical topology which is the method used to pass information between workstations. Logical topology was discussed in the Protocol chapter
A network topology is the arrangement of nodes — usually switches, routers, or software switch/router features — and connections in a network, often represented as a graph. The topology of the network, and the relative locations of the source and destination of traffic flows on the network, determine the optimum path for each flow and the extent to which redundant options for routing exist in the event of a failure. There are two ways of defining network geometry: the physical topology and the logical (or signal) topology.
The physical topology of a network is the layout of nodes and physical connections, including wires ( DSL), fiber optics, and microwave. There are several common physical topologies, as described below and as shown in the illustration.
TYPES OF NETWORK TOPOLOGY
1 Bus topology
2 Ring topology
3 Star topology
4 Tree topology
5 Mesh topology
6 Hybrid topology

Bus Topology

Bus topology is a type of network where every device is connected to a single cable which runs from one end of the network to the other. This type of type of topology is often referred to as line topology. In a bus topology, data is transmitted in one direction only. If the bus topology has two endpoints then it is referred to as a linear bus topology. Organizations using this type of topology will generally use an RJ45 cable to link devices together.
Advantages
There are a number of reasons why bus topologies are widely-used. One of the main reasons is that they are ideal for small networks because they keep the layout simple. You don’t need lots of cables to link devices together and you don’t need to manage a complex topological setup. This doubles up by making bus topologies cost effective because they can be run with a single cable. In the event that more devices need to be added then you can simply join your cable to another cable.
Disadvantages
However, relying on one cable does mean that bus topologies have a single point of failure. If the cable fails then the entire network will go down. A cable failure can cost organizations a lot of time while they attempt to resume service. Further to this, if you have lots of network traffic then the performance of your network will decrease significantly as all the data will be travelling through one cable.
This limitation makes bus topologies suitable only for smaller networks. The primary reason is that the more nodes you have, the slower your transmission speeds are going to be. It is also worth noting that bus topologies are limited in the sense that they are unidirectional, rather than bidirectional like many of the alternative topologies available to you.
Ring Topology

In networks with a ring topology, computers are connected to each other in a circular format. Every device in the network will have two neighbors and no more or no less. The first node is connected to the last node to link the loop together. As a consequence of being laid out in this format packets need to travel through all nodes on the way to their destination.
Within this topology, one node is chosen to configure the network and monitor other devices. Ring topologies are unidirectional but can also be made bidirectional. To make ring topologies bidirectional you would need to have two connections between network nodes to form a Dual Ring Topology. Ring topologies can sustain large networks much more effectively than bus topologies. You can also add a repeater to minimize the presence of packet loss while data is in transit.
Dual Ring Topology

As mentioned above, if ring topologies are configured to be bidirectional then they are referred to as dual ring topologies. Dual ring topologies provide each node with two connections, one in each direction. Thus, data can flow in a clockwise or counterclockwise direction.
Advantages
When using a unidirectional ring topology all data flows in one direction which minimizes the risk of packet collisions. This is compounded by the fact that data can move through nodes at high speeds which can be expanded on when more nodes are added.
Dual ring topologies provide you with an extra layer of protection as they are more resistant to failures. For instance, if a ring goes down within a node then the other ring can step up and back it up. Ring topologies as a whole are low cost to install.
Disadvantages
Even though ring topologies are extremely popular, they are very vulnerable to failure. The failure of one node can take the entire network out of operation. This means that ring topology networks need to be constantly managed to ensure that all nodes are in good health. However, even if your nodes are in good health your network can still be knocked offline by a transmission line failure!
Ring topologies also raise scalability concerns. For instance, bandwidth is shared by all devices within the network. In addition, the more devices that are added to a network the more communication delay the network experiences. This means that the number of devices added to a network topology needs to be monitored carefully to make sure that the network resources aren’t stretched beyond their limit.
Making changes to a ring topology is also complicated because you need to shut down the network to make changes to existing nodes or add new nodes. This is far from ideal as you’ll need to factor in downtime every time you want to make a change to the topological structure!
Star Topology

A star topology is a topology where every node in the network is connected to one central node. Every device in the network is directly connected to the central node and indirectly connected to every other node. The relationship between these elements is that the central network device is a server and other devices are treated as clients. The central node has the responsibility of managing data transmissions across the network. The central node or hub also acts as a repeater. In star topologies, computers are connected with a coaxial cable, twisted pair, or optical fiber cable.
Advantages
Star topologies are most commonly-used because you can manage the entire network from one location: the central hub. As a consequence, if a node that isn’t the central node goes down then the network will remain up. This gives star topologies a layer of protection against failures that aren’t always present with other topology setups. Likewise, you can add new computers without having to take the network offline like you have to do with a ring topology.
In terms of physical structure, star topologies require fewer cables than other topology types. This makes them simple to set up and manage over the long-term. The simplicity of the overall design makes it much easier for administrators to run troubleshooting when dealing with performance faults.
Disadvantages
Though star topologies may be relatively safe from failure, if the central node goes down then the entire network will go down. As such, the administrator needs to manage the health of the central node closely to make sure that it doesn’t go down. The performance of the network is also tied to the central node’s configurations and performance. Star topologies are easy to manage in most ways but they are far from cheap to set up and use
Tree Topology

As the name suggests, a tree topology is a network structure that is shaped like a tree with its many branches. Tree topologies have a root node which is connected to other node hierarchy. The hierarchy is parent-child where there is only one mutual connection between two connected nodes. As a general rule, a tree topology needs to have three levels to the hierarchy in order to be classified this way. This form of topology is used within Wide Area Networks to sustain lots of spread-out devices.
Advantages
The main reason why tree topologies are used is to extend bus and star topologies. Under this hierarchical format, it is easy to add more nodes to the network when your organization grows in size. This format also lends itself well to finding errors and troubleshooting because you can check for performance issues systematically through the tree view.
Disadvantages
Tree topologies have a significant weakness which is the central node. If the central node fails then the entire network goes down. Maintaining the network is not simple either, as the more nodes you add, the more difficult it becomes to manageeverything. Another disadvantage of a tree topology is the number of cables you need. Cables are required to connect every device throughout the hierarchy in a way that is excessive when compared to a simpler format like bus topologies.
Mesh Topology

A mesh topology is a point-to-point connection where nodes are interconnected. In this form of topology, data is transmitted via two methods: routing and flooding. Routing is where nodes use routing logic to work out the shortest distance to the packet’s destination. In contrast flooding, data is sent to all nodes within the network. Flooding doesn’t require any form of routing logic to work.
There are two forms of mesh topology: partial mesh topology and full mesh topology. With partial mesh topology, most nodes are interconnected but there are a few which are only connected to two or three other nodes. A full mesh topology is where every node is interconnected.
Advantages
Mesh topologies are used first and foremost because they are reliable. The interconnectivity of nodes makes them extremely resistant to failures. There is no single machine failure that could bring down the entire network. The absence of a single point of failure is one of the reasons why this is a popular topology choice. This setup is also secure from being compromised.
Disadvantages
However, mesh topologies are far from perfect. They require an immense amount of configuration once they are deployed. The topological layout is more complex than many other topologies and this is reflected by how long it takes to set up. You’ll need to accommodate a whole host of new wiring which can add up to be quite expensive.
Hybrid Topology

When a topology is comprised of two or more different topologies it is referred to as a hybrid topology. Hybrid topologies are most-commonly encountered in larger enterpriseswhere individual departments have network topologies that different from another topology in the organization. Connecting these topologies together will result in a hybrid topology. As a consequence, the capabilities and vulnerabilities depend on the types of topology that are tied together.
Advantages
There are many reasons why hybrid topologies are used but they all have one thing in common: flexibility. There are few constraints on the structure that a hybrid topology cannot accommodate, and you can incorporate ring, bus, mesh, and star topologies into one hybrid setup. As a consequence, hybrid topologies are very scalable. Their scalability makes them well-suited to larger networks.
Disadvantages
Unfortunately, hybrid topologies can be quite complex, depending on the topologies that you decide to use. Each topology that is part of your hybrid topology will have to be managed according to its unique requirements. This makes administrators’ jobs more difficult because they are going to have to attempt to manage multiple topologies rather than a single one. In addition, setting up a hybrid topology can end up being quite costly.
Why we use network topologies?
Importance of network topology
• Plays a significant role in the functioning of networks.
• Helps us better understand the networking concepts.
• Plays a crucial role in performance.
• Helps reduce the operational and maintenance costs such as cabling costs.
• A network topology is a factor in determining the media type to be used to cable a network.
• Error or fault detection is made easy using network topologies.
• Effective utilization of resources and networking components.

Submitted by :Mahrukh Arshad

Roll no :2127-BH-Math-18

Section :G1