This document provides an overview of computer networking concepts including different network topologies, transmission media, and network components. It defines key networking terms like local area network (LAN), metropolitan area network (MAN), wide area network (WAN), and personal area network (PAN). Different network topologies like bus, star, ring, and mesh are described. Common transmission media include coaxial cable, twisted pair cable, optical fiber, and wireless transmission. Network components such as hubs, switches, routers, bridges, and gateways are also explained.
This was made along with a simple research paper in my Network + course. I don't have any negative intention in uploading of this. I only hope it could help in any ways
Module 4
Wireless Wide Area Networks and LTE Technology Design Private and public leased networks. Video conferencing, television and radio broadcast transmissions. Wireless WAN, Cellular Networks, Mobile IP Management in Cellular Networks, Long-Term Evolution (LTE) Technology, Wireless Mesh Networks (WMNs) with LTE, Characterization of Wireless Channels.
Network Topology and Transmission MediaRubal Sagwal
Network Topology, Star topology, ring topology, bus topology, mesh topology. Transmission media. Guided and Unguided transmission media. Wired and wireless medium.
A computer network is defined as the interconnection of two or more computers. It is done to enable the computers to communicate and share available resources.
Components of computer network
Network benefits
Disadvantages of computer network
Classification by their geographical area
Network classification by their component role
Types of servers
This was made along with a simple research paper in my Network + course. I don't have any negative intention in uploading of this. I only hope it could help in any ways
Module 4
Wireless Wide Area Networks and LTE Technology Design Private and public leased networks. Video conferencing, television and radio broadcast transmissions. Wireless WAN, Cellular Networks, Mobile IP Management in Cellular Networks, Long-Term Evolution (LTE) Technology, Wireless Mesh Networks (WMNs) with LTE, Characterization of Wireless Channels.
Network Topology and Transmission MediaRubal Sagwal
Network Topology, Star topology, ring topology, bus topology, mesh topology. Transmission media. Guided and Unguided transmission media. Wired and wireless medium.
A computer network is defined as the interconnection of two or more computers. It is done to enable the computers to communicate and share available resources.
Components of computer network
Network benefits
Disadvantages of computer network
Classification by their geographical area
Network classification by their component role
Types of servers
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Alt. GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using ...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Removing Uninteresting Bytes in Software FuzzingAftab Hussain
Imagine a world where software fuzzing, the process of mutating bytes in test seeds to uncover hidden and erroneous program behaviors, becomes faster and more effective. A lot depends on the initial seeds, which can significantly dictate the trajectory of a fuzzing campaign, particularly in terms of how long it takes to uncover interesting behaviour in your code. We introduce DIAR, a technique designed to speedup fuzzing campaigns by pinpointing and eliminating those uninteresting bytes in the seeds. Picture this: instead of wasting valuable resources on meaningless mutations in large, bloated seeds, DIAR removes the unnecessary bytes, streamlining the entire process.
In this work, we equipped AFL, a popular fuzzer, with DIAR and examined two critical Linux libraries -- Libxml's xmllint, a tool for parsing xml documents, and Binutil's readelf, an essential debugging and security analysis command-line tool used to display detailed information about ELF (Executable and Linkable Format). Our preliminary results show that AFL+DIAR does not only discover new paths more quickly but also achieves higher coverage overall. This work thus showcases how starting with lean and optimized seeds can lead to faster, more comprehensive fuzzing campaigns -- and DIAR helps you find such seeds.
- These are slides of the talk given at IEEE International Conference on Software Testing Verification and Validation Workshop, ICSTW 2022.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Le nuove frontiere dell'AI nell'RPA con UiPath Autopilot™UiPathCommunity
In questo evento online gratuito, organizzato dalla Community Italiana di UiPath, potrai esplorare le nuove funzionalità di Autopilot, il tool che integra l'Intelligenza Artificiale nei processi di sviluppo e utilizzo delle Automazioni.
📕 Vedremo insieme alcuni esempi dell'utilizzo di Autopilot in diversi tool della Suite UiPath:
Autopilot per Studio Web
Autopilot per Studio
Autopilot per Apps
Clipboard AI
GenAI applicata alla Document Understanding
👨🏫👨💻 Speakers:
Stefano Negro, UiPath MVPx3, RPA Tech Lead @ BSP Consultant
Flavio Martinelli, UiPath MVP 2023, Technical Account Manager @UiPath
Andrei Tasca, RPA Solutions Team Lead @NTT Data
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
Climate Impact of Software Testing at Nordic Testing DaysKari Kakkonen
My slides at Nordic Testing Days 6.6.2024
Climate impact / sustainability of software testing discussed on the talk. ICT and testing must carry their part of global responsibility to help with the climat warming. We can minimize the carbon footprint but we can also have a carbon handprint, a positive impact on the climate. Quality characteristics can be added with sustainability, and then measured continuously. Test environments can be used less, and in smaller scale and on demand. Test techniques can be used in optimizing or minimizing number of tests. Test automation can be used to speed up testing.
Generative AI Deep Dive: Advancing from Proof of Concept to ProductionAggregage
Join Maher Hanafi, VP of Engineering at Betterworks, in this new session where he'll share a practical framework to transform Gen AI prototypes into impactful products! He'll delve into the complexities of data collection and management, model selection and optimization, and ensuring security, scalability, and responsible use.
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
- Reduction in onboarding time from 5 weeks to 1 day
- Improved developer experience and productivity through actionable findings and reduction of false positives
- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
- How to deliver security artifacts that matter for ATO’s (SBOMs, vulnerability reports, and policy evidence)
- How to streamline operations with automated policy checks on container images
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
2. A network consists of 2 or more
computers connected together,
and they can communicate and
share resources (e.g. information)
3. • Communications – activity associated
with distributing or exchanging
information
• Telecommunications – technology of
communications at a distance that
permits information to be created any
where and used everywhere with little
delay
A network is a way to get “stuff”
between 2 or more “things”
Examples: Mail, phone system,
conversations, railroad system,
highways and roads
5. Source System Destination System
Sour c e Tr a ns mi t t e r Tr a ns mi s s i on Re c e i ve r
De s t i na t i on
1 2 3 4 5
Wor ks t a t i on/ PC Me di um Wor ks t a t i on/ PC
6. Es s e nt i a l s f or Ne t wor k
• Text input information
• Input data digital bit
stream
• Transmitted analog
signal
• Received analog signal
• Output data digital bit
stream
• Text output information
9. Bus Topol ogy
Bus: each node is daisy-chained
(connected one right after the other)
along the same backbone. Information
sent from a node travels along the
backbone until it reaches its destination
node. Each end of a bus network must
be terminated with a resistor to keep the
10. Ri ng Topol ogy
Similar to a bus network, rings have
nodes daisy chained, but the end of the
network in a ring topology comes back
around to the first node, creating a
complete circuit. Each node takes a turn
sending and receiving information
through the use of a token. The token
along with any data is sent from the first
node to the second node which extracts
the data addressed to it and adds any
data it wishes to send. Then second
node passes the token and data to the
third node, etc. until it comes back
around to the first node again. Only the
node with the token is allowed to send
data . All other nodes must wait for the
token to come to them.
11. St a r Topol ogy
• In a star network, each node is
connected to a central device
called a hub. The hub takes a
signal that comes from any
node and passes it along to all
the other nodes in the network
• A hub does not perform any
type of filtering or routing of
the data
• A hub is a junction that joins
all the different nodes together
12. St a r - Bus Topol ogy
Prob. Most common topology
used today. Combines elements
of the star and bus topologies to
create a versatile network
environment
Nodes in particular areas are
connected to hubs (and create
star topology), and hubs are
connected together along the
network backbone (like a bus
network)
Often you have stars nested
within stars
13. Me s h Topol ogy
It is also called a
point-to-point
topology
Each device is
connected directly to
all other network
devices
It provides fault
tolerance
It is only found in
wide area networks
14. Ot he r ne t wor k t opol ogi e s
Some basic network
topologies not
previously mentioned:
•One-to-one
•Hierarchical
•Hybrid
•Client-server
•Multiple nodes
16. Ne t wor k c onf i gur a t i on
Classification based on
how computers behave in
a network
Two classifications are
•Peer-to-Peer
network
•Server based
network
17. Pe e r - t o- Pe e r ne t wor k
•Nodes provide and
request services
•User in each node
administers
resources
•No extra investment
•Easy to setup
•Very weak security
•Additional load on
19. Advantages of peer-to-peer networks:
• Low cost
• Simple to configure
• User has full accessibility of the computer
Di sadvant ages of peer- t o- peer net works:
• May have duplication in resources
• Difficult to uphold security policy
• Difficult to handle uneven loading
Where peer-to-peer network is appropriate:
• 10 or less users
• No specialized services required
• Security is not an issue
• Only limited growth in the foreseeable
future
20. Cl i e nt s a nd Se r ve r s
Network Clients (Workstation)
Computers that request network resources or services
Network Servers
Computers that manage and provide network resources and
services to clients
Usually have more processing power, memory and hard disk
space than clients
Run Network Operating System that can manage not only
data, but also users, groups, security, and applications on the
network
Servers often have a more stringent requirement on its
performance and reliability
21. Advant ages of cl i ent / server
net works
• Facilitate resource sharing – centrally administrate
and control
• Facilitate system backup and improve fault tolerance
• Enhance security – only administrator can have access
to Server
• Support more users – difficult to achieve with peer-
to-peer networks●
Di s a dva nt a ge s of
c l i e nt / s e r ve r
ne t wor ks
●High cost for Servers
●Need expert to configure the
network
●Introduce a single point of failure
to the system
23. Coa xi a l c a bl e
• Widely installed for use in business and corporation
Ethernet and other types of LANs.
• Consists of inter copper insulator covered by cladding
material, and then covered by an outer jacket.
• Physical Descriptions.
Inner conductor is solid copper
metal
Separated by insulating material
Outer conductor is braided shielded
(ground)
Covered by sheath material
24. Appl i cat i ons:
•TV distribution (cable TV); long distance telephone transmission;
short run computer system links.
•Local area networks.
Transmi ssi on charact eri st i cs:
• Can transmit analog and digital signals
• Usable spectrum for analog signaling is about 400
MHz
• Amplifier needed for analog signals for less than 1 Km
and less distance for higher frequency
• Repeater needed for digital signals every Km
or less distance for higher data rates
• Operation of 100’s Mb/s over 1 Km
25. Twi s t e d Pa i r Ca bl e s
Physi cal descri pt i on:
• Each wire with copper conductor
• Separately insulated wires
• Twisted together to reduce cross talk
• Often bundled into cables of two or four twisted pairs
• If enclosed in a sheath then is shielded twisted pair (STP) otherwise
often for home usage unshielded twisted pair (UTP). Must be shield
from voltage lines
Appl i cat i on:
• Common in building for digital signaling used at speed of 10’s
Mb/s (CAT3) and 100Mb/s (CAT5) over 100s meters.
• Common for telephone interconnection at home
and office buildings
• Less expensive medium; limited in distance,
bandwidth, and data rate
26. Category Maximum data
rate
Usual application
CAT 1 Less than 1 Mbps analog voice (plain old telephone
service) Integrated Services
Digital Network Basic Rate
Interface in ISDN Doorbell wiring
CAT 2 4 Mbps Mainly used in the IBM Cabling
System for token ring networks
CAT 3 16 Mbps Voice and data on 10BASE-T
Ethernet (certify 16Mhz signal)
CAT 4 20 Mbps Used in 16Mbps Token Ring
Otherwise not used much
CAT 5 100 Mbps 100 Mbps TPDDI
Ca t e gor i e s of Twi s t e d Pa i r s
Ca bl i ng Sys t e m
27. Opt i c a l Fi be r s
Physi cal Descri pt i on:
• Glass or plastic core of optical fiber = 2to125 µm.
• Cladding is an insulating material.
• Jacket is a protective cover.
• Laser or light emitting diode provides transmission light source.
Appl i cat i ons:
• Long di s t a nc e t e l e c ommuni c a t i on.
• Gr e a t e r c a pa c i t y; 2 GB/ s ove r 10’ s of Km.
• Sma l l e r s i z e a nd l i ght e r we i ght .
• Lowe r a t t e nua t i on ( r e duc t i on i n s t r e ngt h of
s i gna l ) .
28. ●
Electromagnetic isolation – not effected by external
electromagnetic environment. Aka more privacy.
•Greater repeater spacing fewer repeaters, reduces line
regeneration cost.
• Multimode fiber is optical fiber that is designed to carry multiple light
rays or modes concurrently, each at a slightly different reflection angle
within the optical fiber core.
used for relatively short distances because the modes tend to disperse
over longer lengths (this is called modal dispersion).
• For longer distances, single mode fiber (sometimes called monomode)
fiber is used. In single mode fiber a single ray or mode of light act as a
carrier.
29. Wi r e l e s s Tr a ns mi s s i on
Frequency range ( l i ne of si ght ) :
• 26 GHz to 40 GHz: for microwave with highly directional beam as possible.
• 30 MHz to 1 GHz: for Omni directional applications.
• 300MHz to 20000 GHz: for infrared spectrum; used for point to point and
multiple point application (line of sight).
Physical applications:
• Terrestrial microwave – long haul telecommunication service (alternative to
coaxial or optical fiber).
• Few amplifier and repeaters.
• Propagation via towers located without blockage from trees,
etc (towers less than 60 miles apart).
30. • Satellite is a microwave relay station.
• Geostationary orbit (22,000 miles) and low orbit (12000 miles).
• Satellite ground stations are aligned to the space satellite, establishes a link,
broadcast at a specified frequency. Ground station normally operate at a number of
frequencies – full duplex.
• Satellite space antenna is aligned to the ground station establishes a link and
transmits at the specified frequency. Satellite are capable of transmitting at multiple
frequencies simultaneously, full duplex..
• To avoid satellites from interfering with each other, a 4 degree separation is required
for 4/6 GHz band and 3 degree for 12/14 GHz band. Limited to 90 satellites.
• Disadvantage: not satellite repair capability; greater delay and
attenuation problems
31. Wi r e l e s s LAN
• Wireless LAN.
• Hyper LAN (European standard; allow
communication at up to 20 Mbps in 5
GHz range of the radio frequency (RF)
spectrum.
• Hyper LAN/2 operate at about 54
Mbps in the same RF band.
33. Hubs
•A hub is the place where data converges
from one or more directions and is
forwarded out in one or more directions.
•Seen in local area networks.
34. Ga t e wa ys
• A gateway is a network point that
acts as an entrance to another
network. On the internet, in terms of
routing, the network consists of
gateway nodes and host nodes
• Host nodes are computer of network
users and the computers that serve
contents (such as Web pages)
• Gateway nodes are computers that
control
traffic within your company’s network
35. Rout e r s
• A router is a device or a software in a
computer that determines the next network
point to which a packet should be
forwarded toward its destination
• Allow different networks to communicate
with each other
• A router creates and maintain a table of the
available routes and their conditions and
uses this information along with distance
and cost algorithms to determine the best
route for a given packet
• A packet will travel through a number of
network points with routers before arriving
36. Br i dge
•A bridge is a product that connects
a local area network (LAN) to
another local area network that
uses the same protocol (for
example, Ethernet or token ring)
•A bridge examines each message
on a LAN, "passing" those known
to be within the same LAN, and
forwarding those known to be on
37. Swi t c he s
•Allow different nodes of a network to
communicate directly with each other
•Allow several users to send information
over a network at the same time without
slowing each other down
39. Loc a l Ar e a Ne t wor k ( LAN)
A Local Area Network (LAN) is a relatively small network that
is confined to a small geographic area, such as a single office
or a building. Laptops, desktops, servers, printers, and other
networked devices that make up a LAN are located relatively
close to each other. A key characteristic is that all of the
equipment that comprises a LAN, is owned by a single entity.
40. Me t r opol i t a n Ar e a Ne t wor k
The term Metropolitan Area Network (MAN) is typically used to
describe a network that spans a citywide area or a town. MANs
are larger than traditional LANs and predominantly use high-
speed media, such as fiber optic cable, for their backbones.
MANs are common in organizations that need to connect several
smaller facilities together for information sharing. This is often the
case for hospitals that need to connect treatment facilities,
outpatient facilities, doctor's offices, labs, and research offices for
access to centralized patient and treatment information. MANs
share many of the same security threats as LANs, but on a larger
scale. The plight of an administrator in a central location granting
access to countless offices that are scattered within a city is a
difficult one that demands strict access control
mechanisms to protect against unauthorized
information access.
42. Wi de Ar e a Ne t wor k
A Wide Area Network (WAN) covers a significantly larger
geographic area than LANs or MANs. A WAN uses public
networks, telephone lines, and leased lines to tie together smaller
networks such as LANs and MANs over a geographically
dispersed area. Connecting devices in different geographic areas
together for information sharing, WANs are an important piece
of enterprise networks. For example, consider the Visa Net
global network used by Visa International. The Visa Net network
connects locations throughout 150 countries to validate and debit
credit-card transactions at over 24 million locations. By providing
security and simplicity over a standard-based WAN architecture,
Visa International relies on their network infrastructure to
provide reliable access to merchants who accept Visa
credit cards for transactions.
44. Pe r s ona l Ar e a Ne t wor k
A more recent term used to describe a type of network is a Personal Area
Network (PAN). PAN networks are usually wireless, established in an on-
demand or ad-hoc fashion when needed to communicate between two or more
devices. PAN networks can be used between devices owned by two different
parties, or between two devices owned by one person, such as a PDA and a
laptop or mobile phone. These networks are usually characterized as short-range,
often limited to 10 meters or less in range.
An example of a PAN technology is Bluetooth wireless networking. Bluetooth is
designed as a cable-replacement technology, allowing users to discard the serial
and USB cables used by many of today's peripheral devices and rely on a
Bluetooth PAN for communication. Bluetooth PANs support up to 7 devices in a
single network and can be used for proprietary protocols (such as PDA
synchronization) or standards-based protocols, including Internet
access over IP and the Bluetooth Network Encapsulation Protocol
(BNEP).
Transmitter: modem
Transmission system: public telephone network
Receiver: modem
Destination: server
<number>
Network - A group of computers connected together in a way that allows information to be exchanged between the computers.
Node - Anything that is connected to the network. While a node is typically a computer, it can also be something like a printer or CD-ROM tower.
Segment - Any portion of a network that is separated, by a switch, bridge or router, from other parts of the network.
Backbone - The main cabling of a network that all of the segments connect to. Typically, the backbone is capable of carrying more information than the individual segments. For example, each segment may have a transfer rate of 10 Mbps (megabits per second: 1 million bits a second), while the backbone may operate at 100 Mbps.
Topology - The way that each node is physically connected to the network.
<number>
Similar to a bus network, rings have nodes daisy chained, but the end of the network in a ring topology comes back around to the first node, creating a complete circuit. Each node takes a turn sending and receiving information through the use of a token. The token along with any data is sent from the first node to the second node which extracts the data addressed to it and adds any data it wishes to send. Then second node passes the token and data to the third node, etc. until ti comes back around to the first node again. Only the node with the token is allowed to send data . All other nodes must wait for the token to come to them.
<number>
A hub does not perform any type of filtering or routing of the data. A hub is a junction that joins all the different nodes together.
<number>