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Information Technology Management
Course Code
ITM 301
Franklyn Prescod
Study Guide

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Chapter 1 Uses of Computer Networks
Computer Networks is a computer in which a large number of computers of separate but
interconnected computers do the job
- They can be connected through fibre optics, cooper cable, microwaves, infrared, and
communication satellites
Distributed System are computer that are collection of independent computers but appear to users as
a single coherent system
- A layer of software on top of the operating system, middleware, is responsible for implementing
this model
- Example of the distributed system is the World Wide Web
Business Applications
Ways computer networking help companies
1. Resource sharing is the make all the business applications, data and equipment available for
everyone on the network
- Such as printer, applications, customer records, inventories, and any information available
VPN (Virtual Private Networks) are used to join the individuals networks at different sites into one
extended network
- Allows individual to access information/data that is 15000 km away, it ends the “tranny of
Servers are powerful computed that store data and are maintained by system administrative
Client are simpler computer, which are operated by individuals to access remote data in the server
Client-server model - The clients are connect to a network which is connected to a server
- The client-server model is applicable when they are in the same building or not
- The request from the client goes through the network to the server, which perform the
requested data and send it back
2. Communication Medium are ways employees communicate with other employee
- Email, VoIP (Voice over internet protocol) Skype, desktop sharing (allow two or more individuals
to see and interact with a graphical computer screen)
3. E-commerce is ability to doing business electronically with customers and suppliers
- Book stores, retail stores, movies stores, air lines
Home Applications
- Like companies, homes have the ability to connect to the internet, communicate with people in
the house,
- Peer- to-peer communication are individuals who form a loose group can communicate with
other in the group, there is no fixed division into clients and servers
o Are used to share music videos, photos, videos,
o Instant message (MSN, facebook, twitter)
o Group of people can work to together to create an content (Wikipedia)
- Access to e-commerce because peer-to-peer in a sense that consumers act as buyers and sellers
o B2B Business to Business Microsoft to IBM
o B2C Business to Customer Future Shop to Ragu
o G2C Government to Corporations distributing taxes
o C2C Corporation to Corporation auctioning second hand products
o P2P Peer to peer selling, sharing stuff
- Access to Entertainment though IPTV ( IP television)
o Access to movies, radio and shows through media streaming applications
- Ubiquitous computing is embedding computers into everyday life
o Security systems, sensors, water, electricity and gas to the computer
- RFID (Radio Frequency IDentification)
o Are chips the size of stamp and has information that the RFID meter needs
Example. Credit card, has information able limits, pin # and user

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Mobile Users
- People can send emails, surf the web, tweet, download songs, search for information
- Hotspot always laptops and mobile computer to be connected to the internet
- Text messaging or text is very popular, allow people to send a short message to another mobile
- Smart Phones, Blackberry and IPhone, allows for fast data services and handling phone calls
- GPS (Global Positioning System) help users have a better idea where they are, search for
stores nearby and the local weather
- M-commence - short text message from mobile devices are used to authorize payments for
books, movies, and other small items, and charge on the monthly bill
- Sensor network are made up of nodes that gather and wirelessly relay information they sense
about the state of the physical world
- Wearable computers, smart watches with radio and insulin pumps
Network Hardware
- There are two types of transmission technology:
o Broadcast links
Is a communication channel is shared by all the machines in the network
A packet sent by one user and sent to all machines and after each
machines check if it is the right address field.
An address field within each packet specifies the intended recipient
o Point-to-point link
They connect individual pair of machines
Packets (envelope with a message), are used to move around the network, it
can be in different routes and go through different machines
Point to point transmission with exactly one sender and one receiver are called
When a packet has a special code in the address field, so that it is processed by
all machines, this is called broadcasting
Personal Area Network
- Lets devices communicate over the range of a person
o Ex. Connect the computer to other devices, like printer, mouse, monitor
o These can be connect by wires or by Bluetooth (a short range wireless network)
o They can also be used with RFID on smartcards and library books
Local Area Network
- Is a privately owned network that operates within and nearby a single building like a home,
office or a factory
- It can connect personal computer and customer product to share information
- Companies using LANs called enterprise networking
- Wireless LANs are very popular, because of the trouble of install cable, all you need is a (AP)
Access Point, wireless router or base station
o Which relay packets between computers and the internet
o This standard wireless LAN is called IEEE 802.11 or WiFi, runs speed from 11 to 100
o Wired LAN are faster 100 mbps to 1 gbps, fewer errors, low delays, easier to send signal
- The topology of many wired LANs is built from point-to-point links, called Ethernet, 802.3.
o Each computer is wired to a port, which is connected to a switch, where the switch
sending the address packet the correct computer
o Dividing one physical LAN into to two small LAN
When the switch getting the packet from a computer, it will attach the packet to
the right port, say the marketing port

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- Both wireless and wired broadcast networks are divided into static and dynamic designs
o Static allocation, divide time into discrete intervals and use round robin algorithm,
allowing each machine to broadcast only when its time slot come, which waste channel
capacity when a machine doing nothing
o Dynamic allocation for a common channel is centralized or decentralized
Centralized: there is a single entity (base) that determines who goes next
Decentralized: each machine must decide for itself where to transmit
Metropolitan Area Network
- MAN covers a city
o How it works is that all the computer in the city are connected to a junction box, which
is connected to a head end, which is connect to the Internet/Antenna(for cable)
Wide Area Network
- Spans a large geographical area, often a country or continent
- Host (Computers) are connected by communication subnet or just subnet , which is responsible
for carrying the messages from one computer to another
o The job of the subnet is to carry messages from host to host, just as the telephone
system carries words from speaker to listener.
o The subnet consist of two distinct component:
Transmission lines
Move the bits through copper wire, optical fibre or even radio links
Switching elements
Are specialized computers, known as routers that connect two or more
transmission line, which take the data and send it on a outgoing lines on
which to forward them
o A subset is a collection of routers that are connected to each other and allow packets to
move though them, from the source to the destination
- Host is connect to the router, which is connect to transmission lines and help by subnet
- Two other types of WAN
o Virtual Private Network: instead of transmission lines and subnet, it uses the internet
o The subnet is run by another companies, it is a Internet service provider and it use the
internet to connect with other networks pg 26
- A collection of interconnected networks are called an internetwork or internet
- A common form of internet is a collection of LANs connected by a WAN.
- The only real technical distinction between a subnet and a WAN in this case is whether hosts are
present. If the system within the gray area contains only routers, it is a subnet; if it contains both
routers and hosts, it is a WAN. The real differences relate to ownership and use.
o The Internet uses ISP networks to connect to other networks
- Subnet - is the collection of router and communication lines owned by the network operator
- A network is formed by the subnet and its hosts
- An internetwork is formed when distinct networks are interconnected. In our view, connecting a
LAN and a WAN or connecting two LANs forms an internetwork, but there is little agreement in
the industry over terminology in this area.
Network Software
- Protocol Hierarchies
o *Most networks are organized as a stack in layers or levels and each level or layer is
different in name, function, content and each layer offer certain services to the higher
o When a layer communicates with each other, they have rules and convention used in
the conversation, which is called a protocol.
Violating the protocol makes the communication more difficult
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