This presentation is about a range of computer network that are explained in detail. I recommend you have microsoft powerpoint 2010 or later for smooth running of the presentation. There are also animations in this presentation. Please enjoy, download and follow.
This presentation is about a range of computer network that are explained in detail. I recommend you have microsoft powerpoint 2010 or later for smooth running of the presentation. There are also animations in this presentation. Please enjoy, download and follow.
Elcometer 456 Dry Film Coating Thickness Gauge sets new standards making meas...MM Naina Exports
Elcometer 456 Dry Film Coating Thickness Gauge sets new standards making measuring dry film thickness faster, reliable and accurate Supplied in india by Multilab Chennai
http://www.multilab.biz/testing/elcometer-testing-equipments/dry-film-thickness/elcometer456-separate-coating-thickness-gauge.htm
Product Description:
The new Elcometer 456 Coating Thickness Gauge sets new standards making measuring dry film thickness faster, reliable and accurate; helping you to become more efficient.
The Elcometer 456 is available in four different models: E, B, S and T. Each coating thickness gauge provides the user with increasing functionality - from the entry level Elcometer 456 E, to the top of the range Elcometer 456 T, with memory, alpha-numeric batching and Bluetooth® communication.
Separate models, with their wide range of probes, provide even greater measurement flexibility.
All probes are fully interchangeable; whilst ferrous gauges accept any ferrous probe and non-ferrous gauges accept any non-ferrous probes the dual FNF gauges accept all ferrous, non-ferrous and dual FNF probes
Dinner with Peers was an event curated by Peers.org. Hosted on Dec 2, 2013, Design Thinking Hong Kong and Carshare.hk collaborated to bring this event to Hong Kong. We invited entreprepreneurs, designers, programmers, investors, and many more to join us for a night of sharing and exploring the concept of collaborative consumption. We were surprised to find the number of people in Hong Kong that is already involved in this movement but also surprised that many people are learning about this for the first time.
Design Thinking Hong Kong hopes to continue to support the peers community as we think that this model and concept can build a stronger community and help tackle issues such as sustainability and waste in Hong Kong.
Product Description
The Elcometer 139 Amine Blush Chip Screen Test Kit is a rapid colorimetric test designed solely for the use in the quick and immediate qualitative identification of amine blush (carbamates) on the surface of coatings using small chips or shavings. The presence of amine blush is indicated by a visual change of colour of the test solution when compared with a control sample.
The Elcometer 139 determines whether amine blush is or is not present on the coating’s surface.
Part Number
Description
E139----C
Amine Blush Chip Screen Test Kit
Dimension
172 x 110 x 100mm (6.75 x 4.25 x 4.00”)
Weight
310g (10.9oz)
Packing List
20 x Polystyrene Sampler Test Tubes of 1.0ml (0.035fl oz) buffer solution, 1 x Test tube of Diluent Part A solution, 1 x Test tube of Diluent Part B solution, 2 x Diluent Transfer Pipettes, 3 x Test Part A dropper bottles - containing ACh-E powder (freeze dried), 3 x Test Part B dropper bottles - containing ATC powder (freeze dried), 1 x Test Part C dropper bottle - containing Chromogen DTNB solution, 1 x Scissors
1 x Re-sealable plastic bag for content disposal, 1 x User Guide.
Elcometer 130 Salt Contamination Meter is quickly and accurately measures the...MM Naina Exports
The Elcometer 130 Salt Contamination Meter quickly and accurately measures the level of soluble salts on surfaces.
WebLink - http://www.multilab.biz/testing/elcometer-testing-equipments/surface-cleanliness/elcometer130-salt-contamination-meter.htm
Fast reading rate allows multiple tests to be completed efficiently
Pressure plate ensures a constant and uniform pressure to paper
Automatic detection of paper size and automatic adjustment of reading value
USB and Bluetooth® data output to ElcoMaster™ 2.0 software
Dust and water resistant rugged design equivalent to IP64
Automatic temperature compensation ensures accurate results
Non-oxidising gold plated contacts ensures lifetime accuracy
Stores up to 150,000 readings in 2,500 alpha numeric batches
Fully portable hand-held, ergonomic design ideal for use in the field
User Friendly
Large buttons ideal for gloved hands
Easy to use menus in multiple languages
High and low reading limit indicators
Factory calibrated for immediate use
Accurate
Conductivity measurement to ±1%
Can be used in accordance with National and International Standards
Automatic temperature compensation ensures repeatable, accurate results
Calibration verification tiles
Trend and batch readings graph formats for instant on-screen analysis
Reliable
Repeatable and reproducible measurements
2 year gauge warranty
Supplied with fully traceable Test Certificates
Batch & individual readings are stored with date and time stamp, temperature and size of test paper
Tough
Heavy duty, impact resistant, dust and waterproof design equivalent to IP64
Wipe clean sealed unit ideal for harsh environments
Scratch and solvent resistant display
Efficient
Instant readings allows multiple tests to be completed efficiently
Alpha numeric batch identification
Compatible with ElcoMaster™ 2.0 and ElcoMaster™ Mobile App
Powersave mode with 'tap awake' feature
Calibration offset allows the use of non-pure water up to 2μg/cm².
Powerful
Measuring range up to 50μg/cm² (3000ppm)
USB and Bluetooth® data output
Stores up to 150,000 readings in 2,500 batches
Soluble salt and conductivity meter in one gauge
Calibration Verification Tiles available for verifying the accuracy of the gauge
group of computers connected with each other to share information or resources. A network can be small or a large. it can be created in a building or spread all over the world. Networks are main source of communication all over the world. The most common resource shared today is connection to the Internet.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
CLASS 11 CBSE B.St Project AIDS TO TRADE - INSURANCE
internet network for o level
1.
2. • A computer network is simply a group of
computers that are so connected that resources
can be shared and information can be
exchanged.
• exchange information
• share resource
• wired & wireless
3. • Resource sharing
• Reliability
• Financial benefits
• Better communication medium
• Access to remote database
4. • Local Area Network (LAN)
• Metropolitan Area Network (MAN)
• Wide Area Network (WAN)
• Value-Added Network (VAN)
• Backbone
• Campus Area Network (CAN)
• Home Area Network (HAN)
• Wireless/Mobile Networks
5. • within a room/floor/building/organization
• usually less than 1 km in diameter
6. • sharing of expensive resources such as color laser printers
• high-speed exchange of essential information between key
people in an organization
• increase the range of potential applications
• increase productivity and profitability
7. • financial cost of networking hardware
• requires memory space in each computer
• complex
• lack of control
• security system must be implemented in order to protect
confidential data
• memory intensive programs(RDBMS) are particularly
vulnerable to networking because of memory requirement
8. • restricted geographical area
• relatively high speed than WAN
• private networks
• e.g. Computer Lab
9. • larger than LAN but smaller than WAN
• e.g. cable TV networks
10. • 5-50 KM
• generally not owned by a single organization (biz. purpose)
• large companies/universities with multiple buildings
• acts as a high-speed network to allow sharing of regional
resources
11. • nationwide or worldwide (public network)
• it may also enable LANs to communicate with each other
12. • ensure high-quality, reliable service for end users
• separate each user’s session
• use public transmission media such as telephone lines,
microwave link and satellite links
13. • Remote data entry
• Centralizing information
• Facilitating communications
14. • Hierarchical Networks : configure computers in a hierarchy
(client-server)
• Distributed Data-processing Networks : peer-to-peer
15. • A node is any device connected to a computer network.
• Nodes can be computers, personal digital assistants (PDAs),
cell phones, or various other network appliances.
16. • The most powerful type of computer on the network, that does
all the processing for the user.
17. • It is a personal computers on network that is operated by
network users.
• Each workstation process its own files using its own operating
system.
18. • refers to the difference between the highest and lowest
frequencies of a transmission channel
• In networking, bandwidth or throughput defines the net bit
rate (bit/s, kbit/s, Mbit/s, Gbit/s, etc.)
19. •Bandwidth can be divided into channels thus channel is simply
a portion of bandwidth that can be used for transmitting
data.two ways of allocating the capacity of bounded
transmission media are:Baseband & Broadband.
•Transmission use entire bandwidth for single channel.
• Allow the division of bandwidth into multiple channels.
20. • Network Interoperability is the continuous ability to send and
receive data between interconnected networks providing the
level of quality expected by the end user customer.
21. • an individual that is responsible for the maintenance
of computer hardware and software systems that make up
a computer network
• generally mid-level support staff within an organization and
do not typically get involved directly with users
22. • Initial network planning
• Frequency allocation, predetermined traffic routing to support
load balancing
• Cryptographic key distribution authorization
• Configuration management
• Fault management
• Security management
• Performance management
• Bandwidth management
• Accounting management
23. • a service that employs a variety of tools, applications and
devices to assist human network managers in monitoring and
maintaining networks
• There exist a wide variety of software and hardware products
that help in managing a network by sending them alerts when
they recognize problems.
• Upon receiving these alerts, management entities are
programmed to react by executing operator notification, event
logging, system shutdown and/or automatic attempts at system
repair
• Simple Network Management Protocol (SNMP)
24. • Physical Security Holes : unauthorized physical access
• Software Security Holes : privileged software
• Inconsistent Usage Holes : When a system administrator
assembles ineffective hardware and software such that the
system is seriously flawed from a security point of view
25. • Authorization : access only those resources they are authorized
• Authentication : username & password
• Encrypted Smart Cards : Punch card
• Biometric Systems : Thumb impression, retina eyes
• Firewall : Protection Layer
1. Packet Filter
2. Application Gateway
3. Circuit-level Gateway
4. Proxy Server
27. Repeater
Regenerates and propagates all electrical transmissions between 2
or more LAN segments
Allows extension of a network beyond physical length limitations
Layer 1 of the “OSI model”
Higher
Layers
Physical
Higher
Layers
PhysicalPhysical
Repeater
Network A Network B
29. Bridge/Hub/Switch
Connects 2 or more LAN segments and uses data link layer
addresses (e.g.MAC addresses) to make data forwarding decisions
Copies frames from one network to the other
Layer 2 of the “OSI model”
Bridge/Hub/Switch
Physical 1 Physical 2
Data Link Data Link
Higher
Layers
Physical
Higher
Layers
Physical
Data Link
23-01-88-A8-77-45
Data Link
53-F1-A4-AB-67-4F
Node in Network A Node in Network B
31. Router
Connects 2 or more networks and uses network layer addresses
(like IP address) to make data forwarding decisions
Layer 3 of the “OSI model”
Router
A node in Network B
Higher
Layers
Physical
Higher
Layers
PhysicalPhysical 1
Data Link
Physical 2
Data Link Data Link
A node in Network A
Data Link
Network
145.65.23.102
Network
137.22.144.6 Network Network
32. Gateway/Tunnel
Connects 2 or more networks that can be of different types and
provides protocol conversion so that end devices with dissimilar
protocol architectures can interoperate
Gateway
137.22.144.6
145.65.23.102
Netware
TCP/IP
35. • Router Switch Module(RSM): A router installed as a card in a switch
to perform routing between VLANs
• Terminal Server: A specialized system that connects terminals to a
network
36. • A Digital Field Meter(DFM) monitors logical devices to diagnose
power supply, resource and temperature exceptions.
• Fan
• Temperature Sensor
• Processor
• Memory
• Power Supply
• Voltage Sensor
37. • A logical or physical component of a network device that connects
the device to a network.
• Port: A port has a MAC address but no IP address
• Interface: It may have a MAC address, an IP address, or both.
38. • VLANs are logical links
managed by DFM.
• VLAN is a logical
subgroup within LAN that
is created by software
rather than by manually
moving cables in the
wiring closet.
40. • A client is a single-user workstation running front-end software
that knows how to communicate with the server.
• A server is one or more multi-user processors with shared memory.
• Clients rely on servers for services.
41. • It facilitates the use of graphical user interface(GUI) available on
powerful workstations.
• It allows the acceptance of open systems because of the fact that
clients and servers can be running on different hardware and
software platforms.
42. • If a significant portion of application logic is moved to a server, the
server may become a bottleneck in the processing and distribution of
data to the clients.
• The server’s limited resources will be in ever-increasing demand by
the increasing number of resource consumers.
43. • Novel’s NetWare Operating System: supports TCP/IP protocol
• Windows NT 4.0: supports TCP/IP, IPX, also includes Internet
Information Server (IIS). IIS includes both a web server and an FTP
server.
• Windows 2000 Server: supports IP, IPX, AppleTalk
• IBM OS/2 Warp: It does not include an Internet server, but it does
have a built-in web browser and FTP client.
44. • In this model, the application and the data reside on the file server.
• When a network user needs access the application and data, both
are loaded over network onto that user’s workstation.
• Sending the application and data from the server to the workstation
puts load on the network.
45.
46. • There are several types of physical channels through which data can
be sent from one point to another in a LAN.
• Bounded/Guided Media (Wired)
• Unbounded/Unguided Media (Wireless)
• Media differ in the capability for the following reasons:
1. Noise absorption: Susceptibility to external noise
2. Radiation: Leakage of signal
3. Attenuation: decline of magnitude of signal with distance
4. Bandwidth: transmission speed
47. • Wired media
1. Twisted-pair wire : LAN
2. Coaxial cabling : Cable TV
3. Fiber-optic cabling : Broadband
48. • two insulated copper wires (1 mm thick)
• The purpose of twisting the wires is to ensure that each wire is
equally exposed to any external electrical magnetic field that could
induce unwanted noise.
• commonly used in local telephone communication and for digital
data transmission over short distances up to 1 km. (9600 bps)
50. • being the oldest method, trained manpower is easily available
• In a telephone system, signals can travel several kilometers without
amplification
• can be used for both analog and digital data transmission
• least expensive
• if a portion of a twisted-pair cable is damaged, the entire network is
not shutdown
52. • Category 3 : 4 pairs
• Category 5 : 4 pairs but more twisted with Teflon insulation
• Category 6 : Gigabyte Ethernet
53. • stiff (rigid) copper wire surrounded by an insulating material
• The insulator is encased within a cylindrical conductor (braided
mesh)
• The signal is transmitted by the inner copper wire
54. • Two types:
1. 50-ohm : digital transmission
2. 75-ohm : analog transmission (Cable TV)
55. Terms Implementation
10Base2 Thin Ethernet (RG-58), 10MBPS, 185m cable segment
10Base5 Thick Ethernet, 10MBPS, 500m cable segment(bus)
10BaseF Fiber-optic cable
10BaseT UTP, uses RJ-45 connectors, Star Topology, 100m length
Thick
Ethernet
0.4 inch thick, 1006m
Thin
Ethernet
0.2 inch thick, 165m, normally used for office
installation
56. • better shielding against EMI(Electromagnetic interference) than
twisted-pair cable
• can be used for both analog and digital
• higher bandwidth (noise immunity)
• more expensive than TP but easy to handle
• capable of carrying over 50 std 6MHz color TV channels
57. • Cables that employ copper conductors can easily be breached by
listening equipment.
• If the main consideration is security, then fiber cable is the only
choice to avoid espionage.
58. • newest form of bounded media
• superior in data handling and security
• transmits light signals rather than electric signals
• each fiber has an inner core of glass/plastic that conducts light
60. • Two light sources:
1. LEDs (Light Emitting Diodes)
2. LASERs(Light Amplification by Stimulated Emission Radiation)
Photoelectric
diodes
LED/Laser
61. • Two types:
1. Single-mode fiber (8-10µ (microns) core)
2. Multimode fiber (50µ microns core) 1µ = 10-6 m
Laser
LED
62. • Cost: more expensive than copper cable (associated equipments)
• Installation: difficult to install
• Bandwidth capacity: provides data rates from 100MBPS to 2GBPS
• Node capacity: 75 nodes
• Attenuation: much lower attenuation but has a different problem,
namely, chromatic dispersion
• EMI: immune to eavesdropping
• Mode of transmission: half duplex
63.
64. • handle much higher bandwidth with low attenuation
• not affected by power surges, EMI or power failures
• lighter than copper cable
• do not leak light and are quite difficult to tap (excellent security)
65. • unfamiliar technology requiring skills
• Being unidirectional, two-way communication requires either two
fiber cables or two frequency bands on one fiber
• higher cost
66. Factor UTP STP Coaxial Fiber-optic
Cost Lowest Moderate Moderate Highest
Installation Easy Fairly easy Fairly easy Difficult
Bandwidth 1-155 Mbps 1-155 Mbps 100 Mbps 2 Gbps
Attenuation High (few hundred
meter)
High (few
hundred meter)
Lower (few
kilometer)
Lowest (tens of
kilometer)
EMI Most vulnerable to
EMI and
eavesdropping
Less vulnerable
than UTP
Less vulnerable
than UTP
Not affected by
EMI or
eavesdropping
67. • signals are not guided through a solid medium (Air)
• Radio wave (including VHF and microwave links)
• Satellite links
• VSATs(Very Small Aperture Terminals)
• Infrared and millimeter waves
68. • frequencies between 10 KHz and 1 GHz
• broadcast omnidirectionally or unidirectionally
• The power of the Radio Frequency (RF) signal is determined by the
antenna and trans-receiver.
69. • easy to generate
• travel long distances
• penetrate buildings easily
• omnidirectional
• At low frequency, radio waves pass through obstacles easily, but the
power falls off sharply with distance from source.
• At high frequency, radio waves tend to travel in straight lines and
bounce off obstacles.
• absorbed by rain
70. • Above 100 MHz, the waves travel in straight lines and can,
therefore, be narrowly focused.
• Concentrating all the energy into a small beam using a parabolic
antenna gives a much higher signal to noise ratio, but the
transmitting and receiving antennas must be accurately aligned with
each other.
• uses repeaters at intervals of about 25-30 km to amplify weak signal
71. • do not pass through buildings well
• Multipath Fading (delayed waves may arrive out of phase)
• The higher the towers are, the further apart they can be.
72. • transmission depends on weather and frequency. (10GHz)
• widely used for long-distance telephone communication, cellular
telephones, television distribution
• inexpensive as compared to fiber-optic system (congested area)
• 16 Gbps
74. • use directional parabolic antennas to send and receive signals
• Relay towers and repeaters are used to extend signals
• used whenever cabling is cost-prohibitive such as in hilly areas or
crossing rivers etc.
75. • Frequency range : 4-6 GHz and 21-23 GHz
• Cost : inexpensive for short distance but expensive for long distance
• Installation: difficult due to Line-of-sight requirements
• Bandwidth capacity: 1-10 Mbps
• Attenuation: affected by atmospheric conditions (rain and fog)
• EMI: vulnerable to EMI, jamming and eavesdropping
76. • one antenna is on the satellite in geo-synchronous orbit about
36,000 km above the equator (can reach the most remote places)
• the transmitted frequency is different from the receiving frequency
to avoid interference
77. • Frequency range: 4-6 GHz and 11-14 GHz
• Cost: The cost of building and launching a satellite is extremely
high
• Installation: extremely technical and difficult
• Bandwidth capacity: 1-10 Mbps
• Attenuation: depends on frequency, power, antenna size and
atmospheric conditions. Higher frequency microwaves are more
affected by rain and fog
78. • visible from any point
• transmission and reception costs are independent of the distance
• a transmission station can receive its own transmission (testing)
• cost of placing the satellite
• a signal sent to a satellite is broadcast to all receivers within the
range (security measures need to be taken)
79. • Very Small Aperture Terminals (1m wide antennas)
• the micro-stations do not have enough power to communicate
directly with one another, hence
• a special ground station, the hub, with a large high-gain antenna is
needed to relay traffic between VSATs
80. • connect two LANs in two buildings via lasers mounted on their
roof-tops
• Coherent optical signaling using lasers is inherently unidirectional.
So, each buildings needs its own Laser and photo detector
81. • Advantages:
1. bandwidth is very high at very low cost
2. easy to install
3. does not require any license
• Disadvantages:
1. cannot penetrate rain or thick fog
2. heat from sun causes convection currents
82. • used for short-range communication (remote control in TV)
• directional, cheap and easy to build but do not pass through solid
objects
• Security if Infrared systems against eavesdropping is better than
that of radio systems
• No government license is needed (radio systems must be licensed)
83. Factor LED Laser
Data rate Low High
Mode Multimode Multimode or single-mode
Operating distance 3 Km 30 Km
Lifetime Long life Short life
Temperature sensitivity Minor Substantial
Cost Low Substantial
• Light Source: LED/Laser
• Transmission medium: Fiber-optic cable
• Detector: converter
85. • Two-tier architecture
• Server accepts client requests, process them and return the
requested information to the client.
86. • Characteristics of Client:
1. Activates Master Computer
2. Initiates requests
3. Waits for and receive replies
4. Connects to one or more number of servers at one time
5. Typically interacts directly with end-users using a GUI
• Characteristics of Server:
1. It waits for requests from clients
2. Upon receipt of requests, it process them and then offers replies
3. It usually accepts connections from a larger number of clients.
4. It does not interact directly with end-users.
87. Direct system exchange of resources between linked peers in
network
The most used in the world
Basically different from the Client-server architecture
• e.g. Telephony Traffic
88. Peer to peer is a type of network infrastructure where each computer is both server
and client. In this case, the computers connected to the network share their resources .
• Distributed Architecture • Decentralized architecture
88
89. In a typical peer-to-peer, there is no administrator .So, each
user manages his own post. On the other hand all users can
share their resources as they wish. If we consider one of the
posts as a server, it is intended to share resources, if not it
consumes resources from other posts
89
90. • three categories:
1. Collaborative/Distributed computing: Science and Biotech org.
2. Instant messaging: MSN Messenger or AOL (real-time chat)
3. Affinity communities: search other user’s computers for
information and files like Napster
4. Napster was the name given to two music-focused online services.
It was originally founded as a pioneering peer-to-peer file sharing
Internet service that emphasized sharing audio files, typically
music, encoded in MP3 format.
91. • each computer typically runs both client and server software
• Once you have downloas and install P2P client, you can log into a
Central Indexing Server (indexes all users who are connected to the
server means who are online)
• P2P client will contain an area where you can search for a specific
file.
• The utility queries the index server to find other connected users
with the requested file.
• Once the file download is complete, the connection will be broken.
92. • Each device in a network must have a unique address to be
identified.
• two types of addressing schemes:
1. IP (Internet Protocol) addressing : 192.168.10.51
2. DNS (Domain Name System) addressing : www.google.com
93. • two version of IP Address:
1. IPv4 : 32-bit address
2. IPv6 : 128-bit address
0-255 0-255 0-255 0-255
Octet (4) Period (3)
• two types of IP Address:
1. Static IP
2. Dynamic IP : DHCP
94. IPv4 Classes
A, B, C : Mostly used classes
D : Multicast
E : Broadcast
Class Leftmost bits Start address Finish address
A 0XXX 0.0.0.0 127.255.255.255
B 10XX 128.0.0.0 191.255.255.255
C 110X 192.0.0.0 223.255.255.255
D 1110 224.0.0.0 239.255.255.255
E 1111 240.0.0.0 255.255.255.255
95. • purpose of DNS is to translate domain names into IP addresses
96. • domain name space (tree) is divided into three different sections:
1. Generic domains
2. Country domains
3. Inverse domains
97. • define registered hosts according to their generic behavior (3 chr)
Label Description
com Commercial organization
edu Educational institutions
gov Government institutions
int International organizations
mil Military groups
net Network support centers
org Nonprofit organizations
98. • 2 character country abbreviations
Label Description
us USA
in India
uk UK
ca Canada
au Australia
fr France
100. • HOSTS.txt was used earlier (managed by Stanford Research
Institute International (SRI)
• In 1983, Paul Mockapetris introduce the concept of DNS
• The root of DNS database on the Internet is managed by the
Internet’s Network Information Center (InterNIC).
• The top-level domains were assigned organization wise, and by
country.
101. • Workgroup (P2P) , Domain (Client/Server)
• In a domain, user accounts are defined & managed in a central
database (Security Accounts Manager)
• By default, each domain is a separate entity and do not share
information and resources.
• To allow users to access resources in another domain, you need to
establish a trust between the two domains.
102. • Topology is the method in which networks are physically connected
together.
• It determines the complexity and cost.
• Bus
• Ring
• Star
• Mesh
103. • simplest & oldest used LAN design (passive topology)
• e.g. Ethernet 10Base2 (thinnet)
• can be found in Client/Server system
104. • Advantages:
1. simple, reliable, easy to use (small-sized LANs)
2. requires least amount of cable (less expensive)
3. it is easy to extend a bus (connector)
• Disadvantages:
1. spend a lot of its bandwidth with the computers interrupting
each other instead of communicating
2. difficult to troubleshoot
105. • 1973 by Bob Metacalfe (IEEE standard called 802.3 CSMA/CD)
106. • a section of a network where data packets can collide with one
another when being sent on a shared medium
• the larger the collision domain, the more likely it is that collision
will occur
108. • a data link protocol built into the Macintosh (Apple computer)
• it forms a part of the AppleTalk protocol suite (provide file and
printer sharing services)
• AppleTalk Network Layer
109. • active network, no termination, each node act as a repeater
• can be found in P2P networks
Nearest Active
Upstream Neighbor
Nearest Active
Downstream
Neighbor
110. • Advantages:
1. every computer is given equal access to the token
2. continues to function in a slower manner rather than fail
completely
• Disadvantages:
1. Failure of one computer affects the whole network
2. difficult to troubleshoot
3. Adding or removing computers disrupts the network
111. • IBM created IEEE 802.5 standard known as Token Ring
• it uses a special packet known as Token
• Multi-station Access Unit (MSAU)
112. • another ring-based network but implemented without hubs
• uses multimode fiber-optic cables to implement very fast, reliable
networks
113. • used as a backbone to connect LANs and computers
114. • The possessor of the token is allowed to put a new token onto the
ring as soon as it finished transmitting its frames.
Wrapping
115. • Hybrid hub can accommodate several types of cable (Hybrid Star)
• e.g. Ethernet 10BaseT
• Active Hub(regenerates & require power) and Passive Hub (not req.)
116. • Advantages:
1. easier to modify or add new computers
2. easy to troubleshoot
3. robust
4. use several types of cable
• Disadvantages:
1. if the central hub fails, the whole network fails to operate
2. cabling cost
117. • newest topology, can carry voice & data over network wire or fiber
• transmits all packets as 53-byte cells
• Quality of Service (QoS)
• extremely high-speed
(25-622Mbps or 2.488Gbps)
118. • ATM communicates with cells rather than transmitting frames.
• Instead of specifying the source and destination addresses of the
stations communicating, an ATM cell indicates the path the data will
flow through.
• every station is always transmitting (empty cells)
119. • most often used in large backbone networks in which failure of a
single switch or router can result in a large portion of a network going
down (expensive)
120. • a network that connects the computer and networks within an
organization by using the hardware and software that is used on the
Internet (TCP/IP protocol)
• secure & can have thousands of users
Intranet
(HCL)
Intranet
(Wipro)Internet
Extranet