Title: Telecommunications and Networking
1Telecommunications and Networking
- MIS 503 - Management Information Systems
- MBA Program
-
2A Significant Underestimation
This telephone has too many shortcomings to be
seriously considered as a means of communication.
the device is inherently of no value to
us. Western Union internal memo, 1876.
3Telecommunications The Technology
4AN OVERVIEW OF TELECOMMUNICATIONS AND NETWORKING
Networking the electronic linking of
geographically dispersed devices
Telecommunications communications (voice and
data) at a distance
Page 97-98
5What is communication?
- The Romans used the Latin word communicare when
they meant "to make common, to share, or to
impart. - Communication is the sharing of information or
messages between two or more entities.
6 Elements of a Communication System
- Source - the originator of the message, whether
it is a person or machine. - Transmitter - the equipment that modifies the
message (either data or voice) into the form
required for transmission. - Communications channel - the means of carrying
the signal from the source to the destination.
7Elements of a Communication System
- Transmission media - may be physical, like a
copper wire or fiber optic cable, or atmospheric,
like radio waves. - Receiver - is the device that captures the
message from the communications channel and
converts it into a form that the person or
machine at the destination can understand. - Destination - the person or machine to whom the
message is directed
8Elements of a Communication System
9KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
Analog and Digital Signals
Figure 4.1 Use of Modem in Analog Network
Page 99
10Types of Signals
- Analog signal - a continuous fluctuation over
time between high and low voltage. - Digital signal - discrete voltage state - either
high or low.
11Transmission Modes
- Data can flow between telecommunication devices
in three ways - Simplex - the data can flow only in one
direction. - Half-Duplex - the data can flow in both
directions, but it can only flow in one direction
at any point in time. - Full-Duplex - data can flow in both directions at
the same time.
12KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
Transmission Media
Typical Speeds
Table 4.2 Telecommunications
Transmission Speeds
Page 101
13Data Transmission
- Asynchronous transmission - the data is sent in
packages of characters, one character at a time. - Each character set includes a parity bit
surrounded by start and stop bits. The parity
bit is used for error checking. - Synchronous transmission - data is sent in
packages of more than one character at a time
with each block sandwiched between a header byte
and a trailer byte, called flags.
14KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
Topology of Networks
Page 106
Figure 4.5 Network
Topologies
15More Complex Networks
Page 107
Figure 4.6 vBNS Network Map
16KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
Local Area Networks
- LAN Topologies and Standards
- Contention bus design IEEE 802.3
- Token bus design IEEE 802.4
- Token ring design IEEE 802.5
- Wireless design IEEE 802.11
-
Page 109
17Mesh Topologies
18KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
Types of Networks
- Backbone network terminology
- Bridge connects two LANs using same protocol
- Router (gateway) connects two or more LANs that
may use different protocols - Switch connects more than two LANs using the
same protocols -
Page 113
19Page 112
Figure 4.11 Sample Backbone Network
20Microwave and Satellite Transmission
- A communications satellite is a microwave station
placed in outer space. - Satellites dont bounce the microwave signal
rather, the signal is received and then
rebroadcast at a different frequency. - Satellites can broadcast over long distances.
21A Classic Case of MiscalculationIridium
- Iridium communications
- Launched November 1, 1998
- Went into Chapter 11 bankruptcy on August 13,
1999 - Why?
- Miscalculated competition from cellular
- Development costs were high
- Prices were too high
- Technology was awkward and limited
- The project was mismanaged
- Visit http//en.wikipedia.org/wiki/Iridium_28sate
llite29Quotes for more informaiton
22Other Transmission Options
- Cellular transmission Well, you know about this
one
23Mobile Phone Infrastructure
24Mobile Phone Generations
- 1G The first generation of wireless technology
- used analog communication
- designed for voice communication
- 2G The second generation of digital wireless
technology - Uses digital circuit switched transmission
protocols - Capable of providing voice/data/fax transfers,
albeit at low data rates - SMS was introduced in 1994 and became a popular
tool associated with GSM (Global System for
Mobile communications)
25Mobile Phone Generations (cont.)
- 2.5G Interim wireless technology that has
greater bandwidth - CDMA2000 1x (Code Division Multiple Access) and
GPRS (general packet radio service) - Uses packet switching, which offers high data
transfer rates (e.g., up to 307 kbit/s) compared
to the circuit switching of GSM and other 2G
networks
26Mobile Phone Generations (cont.)
- 3G The third generation of digital wireless
technology - For example, UMTS and CDMA2000 1xEV-DO
- High data transfer rates (2.4Mbit/s)
- It has the potential to support rich media such
as video and graphics
27Mobile Phone Generations (cont.)
- 4G The next generation of wireless technology
- Very high data transfer rates (20 Mbps)
- In the context of mobile phones, it is expected
to be available by 2010 - 4G also refers to the integration of mobile
phones, Wi/Fi networks, and other components of a
pervasive network
28WLAN Architecture
29Wireless Networking Standards
- 802.11 - IEEEs Radio Frequency Wireless
networking standard committee. - 802.11b - uses direct sequence spread spectrum
(DSSS) signaling. Also used the 2.4 - 2.4835 GHz
frequency range and separates it into 14
overlapping 22-MHz channels. - 802.11g - designed to be just as affordable as
802.11b while increasing its maximum capacity
from 11 Mbps through different encoding
techniques. - 802.11a - uses multiple frequency bands in the 5
GHZ range. Like 802.11g, 802.11a provides a
maximum throughput of 54 Mbps.
30WIMAX
- WiMAX is an acronym for Worldwide
Interoperability for Microwave Access - IEEE 802.16d
- WIMAX improves upon the limitations of Wi-Fi by
providing increased bandwidth and range and
stronger encryption - Applications
- An alternative to cable and DSL for last mile
- Connecting Wi-Fi hotspots
- high-speed mobile data services
31Bluetooth
- A mobile wireless networking standard that uses
direct sequence spread spectrum (DSS) signaling
in the 2.4 GHz band to achieve a maximum
throughput of less than 1 Mbps. - Designed to be used on small networks composed of
personal communications devices, also known as
personal area networks.
32Significant Quotes
No sensible man would transact his affairs by a
means of communication such as Bells
telephone. Western Union Board of Directors
letter to shareholders - - October 1876. The
Americans have need of the telephone, but we do
not. We have plenty of messenger boys. Sir
William Preece, chief engineer of the British
Post Office, 1876
33KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
Types of Networks
- The Internet
- Network of networks that use the TCP/IP protocol
- Contain gateways to computers that do not use
TCP/IP - Provides four basic functions
- Electronic mail
- Remote login
- Discussion groups
- Sharing of data resources
-
Page 117-118
34Page 118
Table 4.4 Internet Applications
35KEY ELEMENTS OF TELECOMMUNICATIONS AND NETWORKING
DSL, Cable Modem, and Satellite
- Internet access services
- Digital subscriber line (DSL) service offered
by telephone companies using copper wire already
installed in homes moving data over wires
without disturbing voice traffic - Cable modem connection obtained from cable TV
company using existing home coaxial cable - Satellite most expensive, but may be only
option for customers in rural areas -
Page 120
36KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
Intranets
Intranet a network operating within an
organization that uses the TCP/IP protocol
Page 122
37KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
Internet2 not-for-profit consortium of over
200 universities, working with over 60 technology
companies and the U.S. government, to develop and
deploy advanced network applications and
technologies
Page 122
38KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
- Primary goals of Internet2
- Create a leading-edge network capability for the
national research community - Enable revolutionary Internet applications based
on a much higher-performance Internet that we
have today - Ensure the rapid transfer of new network services
and applications to the broader Internet
community
Page 123
39KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
Network Protocols
Protocol agreed-upon set of rules governing
communication among layers or levels of a network
Page 124
40Major Telecommunications Laws
- Graham Act, 1921
- Exempted telephone companies from antitrust laws
- Communications Act of 1934
- legislation which created the Federal
Communications Commission - ATT Consent Decree of 1956
- ATT and the US Justice department agree on a
consent decree to end an antitrust suit against
ATT in 1949 - Carterfone Decision of 1968
- allowed other businesses to attach telephones,
equipment and business switchboards to the Bell
network - MCI Decision
- FCC decree in 1969 that granted MCI
Communications Inc., as well as any other
company, the right to offer long distance service
to customers and to connect to ATT's network - Modified Final Judgment and Divestiture, 1984
- Split up the Bell Network
- The Telecommunications Act of 1996
41The Telecommunications Act of 1996
- The Telecommunications Act of 1996 was the first
major overhaul of United States telecom policy in
nearly 62 years. The focus of the Act was to
enhance competition - The legislation regulates
- Broadcasting by over-the-air television and radio
stations - cable television operators
- satellite broadcasters
- Wireline telephone companies (local and long
distance), wireless telephone companies, and
others.
42Technology Convergence
43Voice Over IP (VoIP)
- The use of packet-switched networks and the
TCP/IP protocol suite to transmit voice
conversations. - Reasons for implementing VoIP may include
- To improve business efficiency and
competitiveness - To supply new or enhanced features and
applications - To centralize voice and data network management
- To improve employee productivity
- To save money
44VoIP and IP Telephones
- Popular features unique to IP telephones include
- Screens on IP telephones can act as Web browsers,
allowing a user to open HTTP-encoded pages and,
for example, click a telephone number link to
complete a call to that number. - IP telephones may connect to a users personal
digital assistant (PDA) through an infrared port,
enabling the user to, for example, view his phone
directory and touch a number on the IP
telephones LCD screen to call that number. - If a line is busy, an IP telephone can offer the
caller the option to leave an instant message on
the called partys IP telephone screen.
45VoIP and Softphones
46Virtual Organizations
47Technologies for Virtual Teams
48Collaboration-Enabling ToolsGroupware
- Groupware Software products that support
collaboration, over networks, among groups of
people who share a common task or goal - Provide a way for groups to share resources and
opinions
49Collaboration-Enabling Tools Group Decision
Support Systems (GDSS)
- Virtual meetings Online meetings whose members
are in different locations, frequently in
different countries - Group decision support system (GDSS) An
interactive computer-based system that
facilitates the solution of semistructured and
unstructured problems by a group of decision
makers
50Collaboration-Enabling Tools GDSS (cont.)
- Major characteristics of a GDSS
- Its goal is to support the process of group
decision makers by providing automation of
subprocesses using information technology tools - It is a specially designed information system
- It encourages generation of ideas, resolution of
conflicts, and freedom of expression
51Collaboration-Enabling Tools GDSS (cont.)
- GDSSs improve the decision-making process by
- providing structure to the planning process
- support parallel processing of information and
idea generation - make larger meetings possible
52Collaboration-Enabling ToolsTeleconferencing
- Teleconferencing The use of electronic
communication that allows two or more people at
different locations to have a simultaneous
conference - Video teleconference Virtual meeting in which
participants in one location can see participants
at other locations on a large screen or a desktop
computer
53Collaboration-Enabling ToolsTeleconferencing
- Data conferencing Virtual meeting in which
geographically dispersed groups work on documents
together and to exchange computer files during
videoconferences - Web conferencing is conducted on the Internet
- few as two and as many as thousands of people
- allows users to simultaneously view something
- interaction takes place via messaging or a
simultaneous phone teleconference - is much cheaper than videoconferencing because it
runs on the Internet
54SharePoint
- An integrated portfolio of collaboration and
communication services designed to connect
people, information, processes, and systems both
within and beyond the organizational firewall.
(MS Website) - A virtual desktop
- A collaboration space
- Shared workspace
- Communication portal for teams
55Unique Opportunities
That is the essence of virtualization rather
than simply re-creating in digital form the
physical thing we know as a letter, e-mail
reinvents and vastly enhances letter-writing.
Unbound by barriers of time and space and endowed
with new powers, the electronic letter does
something new altogether. The same sort of thing
happens when business, the arts, or government
are reborn in digital form. John Verity,
Business Week, 1994
56Looking into the Future
Computers are getting smaller and smaller. You
can expect to have on your wrist tomorrow what
you have on your desk today, what filled a room
yesterday. Nicholas Negroponte , Being Digital
Todays average consumers wear more computing
power on their wrists than existed in the entire
world before 1961. Anonymous
57Planning for Security and Control
- In todays net-enabled environment, an
increasingly important part of IT planning
involves planning to control and secure the IT
resource
58Control Systems
- The components of control systems are
- Standards for performance
- Sensory determination of actual conditions
- Comparison of standard with actual conditions
- Compensatory action if the deviation is too great
59(No Transcript)
60When there are Failures of Control
- Examples of control breakdowns
- Worldcom
- Qwest
- Global Crossing
- What caused these? Probably, it was in part the
reward systems for senior managers that consisted
of stock options. Managers were rewarded for
inflating the bottom line. - IS has an important role to play in strengthening
control systems - Audits
- Monitoring
- Information dissemination
- Reporting
61Vulnerability of Systems Where Does Control
Fail?
- Errors in and intrusion of the operating system
- Errors in application programs
- Problems with database security
- Lack of network reliability and security
- Problems with adequate control of manual
procedures - Failure of management to maintain proper
organizational control - Open networks and connectivity
- Misuse or mistakes made by users
62Control in the Organization Controls can be
created through
- The structure of the organization
- Decentralized or centralized
- Rewards
- Management committee
- Budget
- Direct supervision
- Routine audits
- Establish and enforce standards and procedures
- Develop a plan and policy for managing database
resources - Data Backup/Recovery
- Data Concurrency Management
- Data Security
63Control in the Organization
64A Key Requirement for Control is Establishing IT
Security
- Without security, the integrity of organizational
IT resources will be at risk therefore,
security is everyones business - Security is an increasingly important issue
because of an increasing number of threats - According to the statistics reported to CERT/CC
over the past several years (CERT/CC 2003) the
number of cyber attacks grew from approximately
22,000 in 2000 to 137,529 2003 - According to the 2004 E-Crime Watch Survey, 43
of respondents report an increase in e-crimes and
intrusions versus the previous year and 70
reported at least one e-crime or intrusion was
committed against their organization
65Security Concepts
- Authentication The process by which one entity
verifies that another entity is who they claim to
be - Authorization The process that ensures that a
person has the right to access certain resources - Confidentiality Keeping private or sensitive
information from being disclosed to unauthorized
individuals, entities, or processes - Integrity Being about to protect data from being
altered or destroyed in an unauthorized or
accidental manner - Confidentiality Keeping private or sensitive
information from being disclosed to unauthorized
individuals, entities, or processes - Nonrepudiation The ability to limit parties from
refuting that a legitimate transaction took
place, usually by means of a signature
66Types of Threats and Attacks
- Nontechnical attack An attack that uses
chicanery to trick people into revealing
sensitive information or performing actions that
compromise the security of a network
67Types of Threats and Attacks (cont.)
- Social engineering A type of nontechnical attack
that uses social pressures to trick computer
users into compromising computer networks to
which those individuals have access
68Types of Threats and Attacks (cont.)
- Multiprong approach used to combat social
engineering - Education and training
- Policies and procedures
- Penetration testing
69Types of Threats and Attacks (cont.)
- Technical attack An attack perpetrated using
software and systems knowledge or expertise
70Types of Threats and Attacks (cont.)
- Denial-of-service (DoS) attack An attack on a
Web site in which an attacker uses specialized
software to send a flood of data packets to the
target computer with the aim of overloading its
resources
71Types of Threats and Attacks (cont.)
- Distributed denial-of-service (DDoS) attack A
denial-of-service attack in which the attacker
gains illegal administrative access to as many
computers on the Internet as possible and uses
these multiple computers to send a flood of data
packets to the target computer
72Types of Threats and Attacks (cont.)
- Malware A generic term for malicious software
- The severity of virus attacks are increasing
substantially, requiring much more time and money
to recover - 85 of survey respondents said that their
organizations had been the victims of e-mail
viruses in 2002
73Types of Threats and Attacks
- Malware takes a variety of forms - both pure and
hybrid - Virus A piece of software code that inserts
itself into a host, including the operating
systems, to propagate it requires that its host
program be run to activate it - Worm A software program that runs independently,
consuming the resources of its host in order to
maintain itself and is capable of propagating a
complete working version of itself onto another
machine - Macro virus or macro worm A virus or worm that
is executed when the application object that
contains the macro is opened or a particular
procedure is executed - Trojan horse A program that appears to have a
useful function but that contains a hidden
function that presents a security risk
74CERT Recommendations for Governing
Organizational Security
- Questions to ask
- What is at risk?
- How much security is enough
- How should an organization
- Develop policies on security
- Achieve and sustain proper security
The CERT recommendations are derived from a
report written by Julia Allen entitled Governing
for Enterprise Security, which may be found at
http//www.cert.org/archive/pdf/05tn023.pdf
75CERT Recommendations for Governing
Organizational Security
- What is at risk?
- Trust that the public has in your organization
- Reputation and brand
- Shareholder value
- Market confidence
- Regulatory compliance
- Fines
- Jail time
- Market share
- Customer privacy
- Ongoing, uninterrupted operations
- Morale of organizational members
76CERT Recommendations for Governing
Organizational Security
- How Much Security is Enough?
- Managements perspective needs to shift
77CERT Recommendations for Governing
Organizational Security
- Good Security Strategy Questions
- What needs to be protected?
- Why does it need to be protected?
- What happens if it is not protected?
- What potential adverse consequences need to be
prevented? - What will be the cost?
- How much of a disruption can we stand before we
take action? - How do we effectively manage the residual risk
when protection and prevention actions are not
taken?
78CERT Recommendations for Evolving the Security
Approach
79CERT Recommendations for Evolving the Security
Approach
80CERT Recommendations for Evolving the Security
Approach
- What Does Effective Security Look Like at the
Enterprise Level? - Its no longer solely under ITs control
- Achievable, measurable objectives are defined and
included in strategic and operational plans - Functions across the organization view security
as part of their job (e.g., Audit) and are so
measured - Adequate and sustained funding is a given
- Senior executives visibly sponsor and measure
this work against defined performance parameters - Considered a requirement of being in business