data communications networking and telecommunications topics for the business student

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Data Communicatio ns Networking and Telecommunications topics for the Business Student

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Data Communications Networking and Telecommunications topics for the Business Student . What is the difference between telecommunications and a network?. TELECOMMUNICATIONS - the of over public or private networks - PowerPoint PPT Presentation

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Page 1: Data Communications Networking and Telecommunications  topics for the Business Student

Data Communicati

onsNetworking and

Telecommunications topics for the Business

Student

Page 2: Data Communications Networking and Telecommunications  topics for the Business Student

What is the difference between telecommunications and a network?

• TELECOMMUNICATIONS - the electronic movement of information over public or private networks

• NETWORK – two or more computers connected together using standards/protocols so that they can work together.

What are the benefits of a network?1. The ability to communicate with others

email is the most popular form of network communications

2. The ability to shareData and Information SoftwarePeripheral devices and other resources Processing

power

Page 3: Data Communications Networking and Telecommunications  topics for the Business Student

What is the most basic way to differentiate networks?

• Local Area Network (LAN) --Connects computers in relatively close proximity

• Wide Area Networks (WAN) -- Connects computers dispersedamong a number of buildings, oreven in different cities.Biggest WAN = the Internet

• Personal Area Network (PAN) --Wirelessly connecting smallpersonal devices, really short distance

By Proximity

Page 4: Data Communications Networking and Telecommunications  topics for the Business Student

Wireless Topology• Computers are connected by radio waves to a

wireless access point (which is directly connected to a wired LAN)– Must be within a certain number of feet from the access

point to communicate wirelessly (35-300 feet depending on the technology being used)

Page 5: Data Communications Networking and Telecommunications  topics for the Business Student

Comparing Wired to WirelessWired Network

• Communications occur using a wired media.

• Faster

• Tends to be more secure• Limited location and hard to

move around (bound to the wire). Limited by walls, furniture, infrastructure.

• Should be able to easily handle multiple users

• Fixed work location• All of the work tools that you

need probably are available

Wireless Network• Communication occurs using radio

signals and line-of-sight base station. Limited by obstructions.

• Slower: rarely reaches max speeds that could be available

• Inherently insecure: security features not turned on: easier to have data packets captured.

• Mobile. Relatively easy to connect to. Must be within range of hotspot (base station)

• One person could monopolize the base station with huge data transfers: slowness for everyone.

• Computer can be set up where needed, but work tools needed may not be available when needed.

Page 6: Data Communications Networking and Telecommunications  topics for the Business Student

Bluetooth vs Wi-Fi (802.11)

802.11802.11b Provides transmission speeds of up to 11 mbps, 300 feet inside, 800 feet outside.

802.11g Provides transmission speeds of up to 54 mbps, at a 35 foot indoor range

802.11a Uses a different radio frequency than standards b & g and other electronic devices (kinda like taking a less crowded route: it will be faster since no one is using it)

802.11n Still being developed: expected to provide transmission speeds over 100 mbps using MIMO technology (multiple wireless signals and antennas):

• Allows for wireless communications within a limited distance: 2 megabits per second, up to 30 feet.

• Less expensive than Wi-Fi chips, consume less power, easier to build into small devices than run on batteries such as cell phones, palm-top computers, and other PDAs.

• Called a “personal area network” (PAN) technology.

• Business networks use 802.11 (Wi-Fi/Wireless Fidelity) while individuals might create their own short range network using Bluetooth Bluetooth

Page 7: Data Communications Networking and Telecommunications  topics for the Business Student

Walt Mossberg Chief Technology columnist for the WallStreet Journal

Q: I’m wondering about wireless specs for a laptop. I suspect the “n” version of Wi-Fi is best but “g” is adequate. Any advice would be appreciated.

A. It depends on how and where you intend to use your laptop’s wireless connectivity. The “n” version of Wi-Fi can be much faster than “g” and can have much greater range. However, the speed difference won’t matter much if your sole use is connecting to the Internet with a typical home or public hotspot service, since the maximum speed of these services is almost always well below “g” and “n” capabilities. But if you are streaming video at home or backing up large files wirelessly among computers and networked hard disks on a home network, you’d be much better off with “n,” assuming all devices involved support it. The same goes for range. In a small apartment, it likely won’t matter. In a large home, it could.

802.11 wireless standards explainedhttp://compnetworking.about.com/cs/wireless80211/a/aa80211standard.htm

http://info.cba.ksu.edu/bkovar/wireless.htm

Page 8: Data Communications Networking and Telecommunications  topics for the Business Student

What are Protocols and what is the difference between them?

• Protocol - a standard that specifies the format of data as well as the rules to be followed during transmission

• Following a certain protocol/standard/set of rules, allows for interoperability– Interoperability - the capability of two or more computer

systems to share data and resources, even though they are made by different manufacturers using perhaps different technologies.

• Two primary communications protocols are TCP/IP and Ethernet– TCP/IP is used for Internet communications– Ethernet is used by computers in a LAN to communicate

Page 9: Data Communications Networking and Telecommunications  topics for the Business Student

Ethernet

• Ethernet - a physical and data layer technology for LAN networking

Page 10: Data Communications Networking and Telecommunications  topics for the Business Student

Ethernet• Defines the wiring and signaling standards used in a

LAN. • Used to describe the hardware layer of a LAN

– Wiring Technology Used (Co-axial, twisted-pair, fiber-optic)– How bits are physically transmitted using those media– Access control rules– Data transmission speeds

• Details multiple user communications and works on the principle of collision avoidance and collision detection.

• Helps insure the compatibility of different devices so that many people can attach to a common cable.

Page 11: Data Communications Networking and Telecommunications  topics for the Business Student

Transmission Control Protocol/ Internet Protocol

• Transmission Control Protocol/Internet Protocol (TCP/IP) - provides the technical foundation for the public Internet as well as for large numbers of private network

• The TCP/IP protocol suite is made up of over 100 different protocols.– The two most important are TCP and IP– TCP provides for data transport functions– IP provides the addressing and routing

mechanism

Page 12: Data Communications Networking and Telecommunications  topics for the Business Student

TRANSMISSION CONTROL PROTOCOL / INTERNET PROTOCOL

(TCP / IP)• Allows computers to exchange messages regardless of

their operating system or hardware. • Transmission Control Protocol

– Breaks information into data packets– Reassembles packets when received– Checks for lost packets

• Internet Protocol– Each computer given a unique IP address– Used to identify a specific computer–209.1.144.212

Page 13: Data Communications Networking and Telecommunications  topics for the Business Student

TCP/IP’s four-layer reference model

• The application layer allows users and applications to access network services– File transfer protocol (FTP)– Simple mail transfer protocol (SMTP)– Telnet provides terminal emulation that allows a “dumb terminal with no

processing capability” to be able to connect to a host computer (which will control everything).

– Hypertext transfer protocol (HTTP)– Simple network management Protocol (SNMP)

Page 14: Data Communications Networking and Telecommunications  topics for the Business Student

TCP/IP’s four-layer reference model

• The Transport layer handles end-to-end packet transportation.

• The Internet layer handles the packets (creation, labeling and addressing, etc.)

• The Network Interface layer details how data is physically sent through the networking hardware.

Page 15: Data Communications Networking and Telecommunications  topics for the Business Student

How Does the Internet Work??http://www.howstuffworks.com/web-server.htm#1 Browser breaks URL into 3 parts

#2 Browser communicates with name server to get IP address#3 Browser connects to specific server, uses GET request to ask for file you wish to see.

#4 Server sends HTML text to your browser. HTML tags are read and page displayed.

209.1.144.212

Page 16: Data Communications Networking and Telecommunications  topics for the Business Student

What is a VPN?• You can build your own

wired network or you can lease lines from a national provider.

• Virtual private network (VPN) - a way to use the public telecommunication infrastructure (e.g., Internet) to provide secure access to an organization’s network– Tunneling software is used to create a private connection

between two different servers or between a server and individual computers (made when needed and terminated when transmission is completed).

– Data packets are encrypted for security.

Page 17: Data Communications Networking and Telecommunications  topics for the Business Student

Network Data Transfer Process: How does it happen?• Network operating system at the source divides the message to be sent

into segments of predetermined length called packets.• Network operating system at the source uses a communications

protocol to label and address each packet.• Network Operating System at the source sends packets over the

network.• Packets are routed as necessary through the network depending on the

transmission mediums, transmission signal characteristics and access control methods.

• Network Operating system at the destination receives packets over the network.

• Network Operating system at the destination identifies and reassembles the packets of the message by looking at the communication protocol information. Requests retransmission of any missing data.

Page 18: Data Communications Networking and Telecommunications  topics for the Business Student

Routers are responsible for determining the path that messages take from the sendingcomputer to the destination computer.

Connecting Networks

Router

The connection between a LAN and a larger network is usually accomplished using a device called a router. Routers are used to connect computers in a network. They also “sit” between your network and other networks (serving as a gatekeeper both into and out of your network). They are intelligent connecting devices that examine each packet of data it receives and then decides which way to send it onward toward its destination

Router

WAN or Backbone

LAN

LAN

Page 19: Data Communications Networking and Telecommunications  topics for the Business Student

Wide Area Network

RR

R

R

R

R

R

RR

R

R

RR

Packet Switched NetworkData is packaged in packets for transmission.

Each packet followsit’s own path through

the network.

Packet-switching occurs when the sending computer divides a message into a number of efficiently sized units called packets, each of which contains the address of the destination computer.

Page 20: Data Communications Networking and Telecommunications  topics for the Business Student

WANs

High Speed Backbone

Backbone is usually a type of network that has a larger size limit and is relatively high speed.

Once a network is linked to a backbone, it becomes part of the Internet community.

Page 21: Data Communications Networking and Telecommunications  topics for the Business Student
Page 22: Data Communications Networking and Telecommunications  topics for the Business Student

Internet Backbone on the Ocean Floor

Page 23: Data Communications Networking and Telecommunications  topics for the Business Student

What are the different types of

LANs?Peer-to-Peer

Each user can share a portion their computer’s hard drive with other LAN users

Client/ServerOnly resources on specific computers called “servers”can be shared

Page 24: Data Communications Networking and Telecommunications  topics for the Business Student
Page 25: Data Communications Networking and Telecommunications  topics for the Business Student

Client/Server Networks• Client - a computer that is designed to request

information from a server• Server - a computer that is dedicated to providing

information in response to external requests

• Client/server network - model for applications in which the bulk of the back-end processing takes place on a server, while the front-end processing is handled by the clients

Page 26: Data Communications Networking and Telecommunications  topics for the Business Student

The Client/Server Model

Storage and management of the data needed by the application (the database)Data Management

PresentationThe user’s interface to the application (how the application appears to the user, including the formatting)

Business Logic

Actual business rules implemented as software (how you implement your software to get the job done and what are the processing steps)

Page 27: Data Communications Networking and Telecommunications  topics for the Business Student

Client/Server Model: A Business View

The different Client/server implementations differ according to:

1. Where the processing for the presentation of information occurs

2. Where the processing of logic or business rules occurs

3. Where the data management component (DBMS) and information (database) are located

Page 28: Data Communications Networking and Telecommunications  topics for the Business Student

Flexible Applications

Server Client

Data Management

Business Logic

PresentationBusiness LogicData Management

PresentationBusiness Logic

Page 29: Data Communications Networking and Telecommunications  topics for the Business Student

Any Combination is Possible

Design Server

Client

Production ServerBusiness Logic

Data Management

PresentationData Management

Business Logic

Page 30: Data Communications Networking and Telecommunications  topics for the Business Student
Page 31: Data Communications Networking and Telecommunications  topics for the Business Student

• Application can be structured to match organizational requirements since it is both flexible and scalable– Can change the implementation of this model as the organization

changes in size since the Client/Server model provides the flexibility to mold information systems to whatever business model is most appropriate for an organization.

• Data access is transparent to the user regardless of where the data is stored.

• Separate programs are more easily maintained and can be reused.

• One central location to go to for all of the sharing and easier to control the entire network.

Client/Server Advantages

Page 32: Data Communications Networking and Telecommunications  topics for the Business Student

Client/Server Disadvantages

• All shared resources reside on computers call “servers” – If a disaster occurs on the server all the data is in

jeopardy– If the server malfunctions, no one can use the network

• Expensive– Usually require expensive hardware and extra staff to

manage– Only 30% of client/server costs are tied up in hardware

and software.– The remaining 70% is in the form of labor - both IT

professionals and knowledge workers.

Page 33: Data Communications Networking and Telecommunications  topics for the Business Student

Current Events in Information Technology

Page 34: Data Communications Networking and Telecommunications  topics for the Business Student

Researchers explore scrapping and rebuilding the Internet

• In order to address the problems that were not envisioned when the Internet was initially created, some are suggesting rebuilding the Internet using a “clean slate” approach.

• Security– The Internet was designed to be open and flexible and all

users were assumed to be trustworthy. Internet protocols were not designed to authenticate users and their data. Firewalls and spam filters are now being used to control security.

– Solution: data not passed along until authenticated

Page 35: Data Communications Networking and Telecommunications  topics for the Business Student

• Mobility– Initially, computers were fixed in location so IP addresses were assigned to

devices in a fixed location. Wireless mobile computing is presenting challenges related to data flow.

– Solution: Reconfigure the IP address system so that addresses are based on the device, rather than the location.

• Ubiquity (also called Pervasive Computing)– When the Internet was first designed, there were relatively few computers

connected to it. The addressing system has become strained due to the proliferation of personal computers and mobile devices.

– Solution: assign addresses to fewer devices and have those same devices connected to an addressed gateway, which is then connected to routers and the rest of the Internet

• Result is fewer devices to keep track of and improved efficiency.

• These changes may happen over the next 10-15 years. They will not be cheap (expected to cost millions and billions of dollars as computer hardware and software and Internet infrastructure are replaced)