© N. Ganesan, Ph.D. , All rights reserved.
Chapter
Communication Trends and Applications
Chapter Objectives
• Describe the status of information communication past and present
• List the factors that led to the growth of computer communications
• Outline a few sample communication applications
• Discuss the evolution of Wide Area Network communications and its current convergence to digital technology
© N. Ganesan, Ph.D. , All rights reserved.
Module
Information Communication Past and Present
Communication in the Past
• Known as Data Communications– Mostly concerned with alphanumeric
data
• A highly specialized topic• Focus
– Mainframes– Analog telecommunication technology – WANs
Communications at Present
• Known as Information Communication– Data, image, audio and video
communications
• A necessary topic for IT professionals• Focus
– Microcomputers – Digital communication technology– LANs, WANs etc.
• Internet– Internet, Intranet and Extranet
Data and Information Communication
Data Information
Image AudioComputer
Data Video
Real-time streaming
Audio and Video Transmission
• Requirements– More bandwidth is required– Real-time transmission may also be
required• Solution
– Compression– Streaming
• Note: Streaming includes compression as well
Comparison of Data and information Communication
Data and Information Communications
Data Communications Information Communications
Alphanumeric data Data, image, audio and video
Mainframe focused Microcomputer focused
Analog technology Digital technologySpecialized topic General topicPrivate network based Internet basedWANs LANs and WANsSeparate Voice and Data
Voice and Data together
Key Words
• Mainframe• Centralized• Analog• Data• Telecommunicatio
n network
• LANs• Distributed• Digital• Information• Computer
network (Internet)
Hosting Services
• Godaddy• 1&1• MediaTemple • Yahoo hosting service
Homework
• Difference between Internet, Intranet, Extranet
• Explore Godaddy and other hosting services
• Download, install and experiment with Microsoft Encoder and Audacity– Convert between different audio file
formats
End of Module
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Module
Opportunities and Certification
Opportunities in Communications
• Specialized knowledge is required for specialist in the communication field– Example: Network Engineer– Certification examinations are available
for attesting to the special skills
• Some knowledge of communications is required of all in the computer field
Certification
• Microsoft Certification– MCSA & MCSE
• CISCO Certification etc.• Network+ Certification • Different vendors offer certifications at
different levels of expertise– Contact their web sites for further
information
Certification Websites
• Microsoft– http://www.microsoft.com/learning/m
cp/certifications.mspx
• CISCO– http://www.cisco.com/en/US/learning/l
e3/learning_career_certifications_and_learning_paths_home.html
Key Words
• Microsoft certifications– MCS*
• CISCO certification• Network+
End of Module
© N. Ganesan, Ph.D. , All rights reserved.
Module
Information Communication Growth Factors
Information Communications: Growth
Factors• Internet• Fast access technologies for the Internet
ramp• Emergence of microcomputers as a
serious business and home computing tool and the focus on connectivity
• Move from large mainframe based infrastructure to LAN based structures
• Client-server computing architectures• Emerging concept of terminal servers
Growth Factors Continued
• Home networking• Digitization of telecommunication
lines• Wireless networking• Multimedia on the Internet • Internet security• Virtual Private Network• Voice over IP (VoIP)
Homework
• Fast access technologies– DSL, Cable, T1, T3, OC1, OC2– Home fiber connections
• IBM business computers– Replacements for mainframes
End of Module
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Module
Evolution Physical Network Architecture
Evolution
• Physical architecture– From mainframes to LAN based
• Functional architecture– Centralized mainframe based architecture
to LAN based client-server architecture– In the case of LAN based architecture,
client-server evolved following the initial introduction of the peer-to-peer network architecture
– Client-server architecture is now followed by terminal server architecture
Early Mainframe-based Centralized Architecture
Mainframe
ModemServer
External AnalogLines
Front End ProcessorMini-Computer
Term. Term.
ConcentratorTerm.
Distributed LAN Based Architecture
Fiber Optic Backbone(FDDI) or Switched Network
Connectivity
Mainframe/Minicomputer
Systems
LAN
LAN
WAN (Internet) Gateway(TCP/IP)
ModemGateway
External Digital/Analog Lines
Current Trend in Distributed Architecture
Source:CISCO
Major Components of the Distributed Architecture
• Clients• Servers• Network interface cards• Cables (copper and fiber)• Switches• Routers• Internet ramps• Internet
Key Words
• Mainframe based• Centralized• Distributed• Fiber ring
• Fiber switches
End of Module
Homework
• Explore some of the Catalyst switches at Cisco
© N. Ganesan, Ph.D. , All rights reserved.
Module
Evolution of the Network Functional Architecture
Network Architectural Evolution
• Mainframe• LAN
– Peer-to-Peer– Client Server
•File server•Application server•Terminal server
Peer-to-Peer Networking
• Initial architecture of the LAN prior to client-server architecture
• Each client operates on equal footing in sharing resources
• Unlike the client-server architecture, there is no server on the network in peer-to-peer networking
P2P Sharing
• Basic sharing is supported– Files– Printers– Internet connection
• Large scale sharing of databases and other business applications are not included in P2P sharing
Client-Server Evolution
• Client-server architecture is always identified by the presence of a server
• The evolution of client-server can be traced to three sub-architectures that are based on the functional feature of the server – File server– Application server– Terminal server
Preview of File Server Computing
Back-end data storage.
Front-end computing
Server
Clients
All the processing of the application is done at the client.
Preview of Application Server
Computing
Back-end data storage and local retrieval of data.
Front-end interface and data manipulation tools.
Server
Clients
Application processing is shared between the client and the server.
A Preview of Terminal Server Computing
Powerful Terminal Server
Thin Clients
Front end processing limited to terminal operations
Extensive back-end data storage, retrieval and
Processing
Factors Used in the Comparison of Architectures
• Point of execution of applications• Network traffic• Security• Hardware/Software requirements• Total Cost of Ownership (TCO)
Path of Evolution
CentralizedMainframe
Peer-to PeerDistributed
Network
ApplicationServer
Terminal Server
More power to the user
Better management of shared dataReduced cost of ownership
File Server
Homework
• Browse for wiring closet, RJ-45 patch cables, wiring rack, punch block etc.
End of Module
© N. Ganesan, Ph.D. , All rights reserved.
Module
Digitization of Telecommunication Lines
Digitization Of Telecom Network
• Initial telecom network was based on analog technology– Copper wire– Electronic transmission– Coaxial cables and twisted pair cables
• Current telecom– Copper wires and fibers– Electronic and optical transmission– Fiber cables and twisted pair cables
Digital WAN Carrier Technologies
• DSL• ISDN• T1, T3 etc.• OC1, OC3 etc.
WAN Communication Technologies
• FDDI and CDDI• Frame Relay• Asynchronous Transfer Mode
(ATM)
Voice Transmission
• Past is based on analog technology• Currently, it is moving to digital
technology– VoIP
Access Speeds• Fastest speed of an analog modem is
around 56K bps• Newer and mostly digital access
technologies such as DSL can operate at faster speeds– Download speed is usually in Mbps– Upload speed is in Kbps
• ADSL and SDSL– In SDSL both upload and download
speeds are the same
Typical DSL Speed
• Upload– 128K bps
• Download– 1.3M bps
Some DSL Providers
• Covad– http://
www.covad.com/products/access/dsl.shtml
• SBC– http://www02.sbc.com/DSL/
• DSL Extreme
Testing the Access Speed
• The current bandwidth of a connection can be tested by accessing websites that test the connection speed– www.dslreports.com – www.2wire.com
Access Security
• www.grc.com
Summary of Access Technologies for the
Internet
Cable
Mod
em
Direct
Satell
ite A
cces
s
xDSL
ISDN
End of Module
© N. Ganesan, Ph.D. , All rights reserved.
Module
Internet Architectures
Architectures
• Internet• Intranet
– An Internet restricted to the company’s own perimeter
• Extranet– Intranet extended to include outside
organizations dealing with the organization
InternetServiceProvider
(ISP)
Internet Defined
Internet Backbone run by major carriers
(TCP/IP etc.)
IndividualsSOHOUser
CompanyNetwork
InternetServiceProvider
(ISP)
Intranet Defined
Internal Company Backbone(TCP/IP)
Mini or MainframeComputer systems
DepartmentalComputerSystem
DepartmentalLAN
Internet
Firewall
Internet
Extranet Defined
Company’s Intranet
Business Associates
Other businessesdealing withcompany A.
Virtual Private Network (VPN)
A Note on VPN
• Created by tunneling into the public network
• Tunneling is done largely by encrypting the computer data
Virtual Private Network (VPN)
Internet
Company’s Intranet
Point-to-Point Tunneling Protocol
(PPTP)Fire Wall
End of Module
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Module
Internet Access
Access
• Analog Access• Digital Access• Remote execution• Telecommuting
Analog Internet Access
Gain access to the resources on the WWW.
Software: Web Browser
Micro Modem
Serial Port
Internet
Access provider
ISP
Digital Internet Access
Gain access to the resources on the WWW.
Software: Web Browser
MicroDSL
Modem
Network Port
Internet
Access provider
ISP
Computer to Computer Access
PublicSwitched
Network (PSN)
Gain access to a company’smainframe to run Unix applications
Micro Modem
Micro Modem
Software: ProComm Plus, Hyper Terminal, PCAnywhere, Remote Desktop
Telecommuting
PSNMain Office
SatelliteOffice
Home
Terminal Services
Terminal Services
Terminal Server
Telecommuting Options
• Employer supported– Previous example falls into this category
where the employer provides access to the office computer from home
– Example: Terminal services• User initiated
– Gain access to one’s computer in the office
– A remote control software is required– Examples: XP Remote Desktop and
GoToMyPC
Some Communication Software
• Hyper Terminal• Telnet• FTP• Procomm Plus• Remote Desktop
Homework
• Dlink home network router• Linksys home network router
Remote Operation
• Gotomypc• logmein
End of Module
© N. Ganesan, Ph.D. , All rights reserved.
Module
Networks
Computer Networks
• Simple – A single LAN
• Intermediate – Departmental
• Enterprise – Campus LANs and organizational LANs
• Advanced – WANs such as an Internet based Virtual
Private Networks (VPNs)
Typical Wired LAN
Client 1 Client 2 Client 3
Server:Network OS,Applications,
Data etc.
Server Operating System
Client OS
Windows2000/2003,Linux
Windows XP/Vista; Linux
Switch
Typical Wireless LAN
Client 1 Client 2 Client 3
Server:Network OS,Applications,
Data etc.
Client OS
Windows2000/2003Server,Linux
Windows XP/Vista; Linux
Wireless NIC
Wireless AccessPoint
Some LAN Applications
• Share business applications• Share data• Share printers, modems etc.• Share the Internet and Internet resources• Send electronic-mail• Engage in audio/video streaming and
conferencing• Act as the infrastructure for the .net or J2EE
architecture
End of Module
© N. Ganesan, Ph.D. , All rights reserved.
Module
Network Security
Network Security
• Network security is an important issue given the fact that many computers are connected to the Internet using broadband connections
General Security Threats
• Viruses• Denial of service attack• OS vulnerabilities• E-mail vulnerabilities• Macro execution vulnerabilities• Ect.
General Security Measures
• Anti-virus • Anti-spyware• Anti-spam software• Firewalls
– Both software firewalls and hardware firewalls can be installed
Secure Communications
• Cryptography– Encryption
• Virtual Private Network (VPN)• IPSec and other secure protocols• Digital signatures
Examples of Protocols for Secure VPN
• PPTP• IPSec with encryption• IPSec with L2TP• SSL with encryption
Examples of Protocols for Trusted VPN
• MPLS with constrained distribution of routing information through BGP ("layer 3 VPNs")
• Transport of layer 2 frames over MPLS ("layer 2 VPNs")
(Source: http://www.vpnc.org/vpn-standards.html )
Encryption
• PKI• RSA ?• MD5 ?• PGP• SSH• HTTPS• DES• AES
End of Module
© N. Ganesan, Ph.D. , All rights reserved.
Module
Wide Area Networks
WAN: The Early Days
• Telecommunication needs– Centered on analog technology
• Data communication needs– Centered around digital technology
• Digital to analog interface– For long distance computer
communications
Long-distance Communications
Digital Digital
Modulation
Plain Old Telephone Service (POTS)
Analog
Interface
Initial WANs
• Overcome the limitations of general purpose analog telephone lines
• Better conditioned lines such as leased lines were used on the network segment
• Driven by a collection of computers to route the data traffic from its source to its destination
• Arpanet was the first WAN that was created
A Summary of the Basic Components of the WAN
Leased lines
Computers/Routing algorithms
Routing devices
Present Status of WANs
• Information is carried in digitized form
• Digital communication lines– Over copper wire– Over fiber-optics
• Digital merger– Telecommunications– Computer communications
WANs: Present and Future
• Fully digital• Technologies
– Frame Relay– ATM
• Point-to-point digital communication will become the norm
ATM operating at severalhundred Mbps
Emerging WAN
DigitalRamp
BusinessComputer System
ATM Switches
High speed digital lines:OC3, OC48 etc.
Summary:Possible Convergent Technology
• Networks– Local– Enterprise– Wide area– Global
ATM
Point-to-point ATM connection may becomepossible?
ATM Possibility
Server
Client 1 Client 2
25 Mbps
ISP100 Mbps
Internet Backbone
1 Gbps
300 Mbps
Likely Scenario
• Ethernet on the desktop• Possibly, ATM on the backbone
Ethernet Challenge
10 Gbps
1 Gbps(Gigabit)
100 Mbps(Fast)
10 Mbps
1 Mbps(Past)
Client 2
10 Mbps/100 Mbps/
1 Gbps/10 GbpsServer
ISP
Client 1
Hub
Current Ethernet Speeds
• 1G bps used widely• 10G bps is gradually gaining
grounds• 100G bps is on the horizon
Net Result
• At the local level (LAN) Ethernet will remain the technology of choice for the foreseeable future
• At the WAN level, ATM will dominate over other WAN technologies
The Digital Future: Fusion
• Digital fusion– Computing– Telecommunications
• Use of computers and the Internet in all forms of communications that would include data as well as all forms of media – An example is Voice over IP (VoIP)
Possible Scenario
• IP based universal digital communication over the Internet with IP addresses as the point of identification– Data, voice and video communication
will be done over the Internet
Explore High-speed Internet
• 10 Gpbs solutions
End of Module
© N. Ganesan, Ph.D. , All rights reserved.
Module
Sample Applications
Some Application Areas
• Networking– Various server applications such as
database server application, messaging server application etc.
• Web hosting and E-commerce • Voice over IP (VoIP)• Network Security
End of Module
© N. Ganesan, Ph.D. , All rights reserved.
Module
Voice over IP (VoIP):Effect of Evolution
Voice Over IP (VoIP)
• VoIP is the digital replacement for the traditional analog phone line
• VoIP is based on the Internet – It is packet switched as opposed to
the traditional phone service that is circuit switched
Voice Over IP Growth
• Growth of VoIP is fuelled by the economy of using the Internet and the technological advantage of the digital technology
• It signifies the inevitable use of digital technology and the Internet to carry voice
• VoIP is poised to grow and probably become the de facto public voice carrier technology
VoIP Challenges
• Latency inherent to the IPv4 protocol
• Availability of bandwidth
VoIP Remedies
• Newer protocol such as IPv6 is designed to address latency
• Faster Internet backbones such as those using Optical Carrier (OC) lines and ATM transport technologies are being introduced to increase the bandwidth of the communication lines
Long Term Developments
• Indications are that residential connections in the long term would evolve into Internet connections replacing the phone connection
Business and Residential End Points
• Instead of identifying an end point in a business or a residence with a phone number, it is plausible that the end point could be identified with a number similar to an IP address
VoIP Application: Broadband Phone
• Broadband phone may be touted as the first real sign of convergence between computer and telephone networks
• VoIP application in the form of broadband phone will also contribute to the growth of communication on the Internet
Broadband Phone
• Uses a DSL or cable modem connection
• Sample vendor– Vonnage
• Broadband phone is known as an Internet appliance
Emergence of Internet Appliances
• Internet appliances are devices that can be used without explicit programming
• The software code necessary will be stored in firmware in the appliances
• Functionalities of the appliances could well be chosen with the use of buttons that may resemble the buttons on a telephone dial pad
Internet Appliances
• A broad range of Internet appliances will then become available for residential use with the broadband phone featuring prominently as perhaps the most used Internet appliance
• Other Internet appliances may include Radios, Interactive TV, Evolving Palm Pilots etc.
End of Module
End of Chapter
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