Transcript Lecture 1 - Lyle School of Engineering

Spring 2006
EE 5304/EETS 7304 Internet Protocols
Course overview
Tom Oh
Dept of Electrical Engineering
[email protected]
TO 1-17-06 p. 1
Course Info
 Class: Tu 6:30-9:20PM, Caruth 128
 Email: [email protected]
 Website: http://www.engr.smu.edu/eets7304/
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Course Info (cont)
 Textbook: D. Comer, R. Droms, Computer Networks
and Internets with Internet Applications, 4th ed.,
Prentice Hall, 2004
 Packaged with lab book, Hands-on Networking with
Internet Technologies
 Slides will be handed out in class and put on website
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TCP/IP References (not required)
 R. Stevens, TCP/IP Illustrated, Vol. 1: the Protocols,
Addison-Wesley, 1994
 D. Comer, Internetworking with TCP/IP - Vol. 1:
Principles, Protocols, and Architecture, 4th ed., Prentice
Hall, 2000
 R. Stevens, B. Fenner, A. Rudoff, Unix Network
Programming, Vol. 1: the Sockets Networking API, 3rd
ed., Addison Wesley, 2004
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General Networking Texts (not required)
 A. Tanenbaum, Computer Networks, 4th ed., Prentice
Hall, 2003
 J. Kurose, K. Ross, Computer Networks: A Top-Down
Approach Featuring the Internet, Addison Wesley, 2001
 W. Stallings, Data and Computer Communications, 7th
ed., Prentice Hall, 2003
 L. Peterson, B. Davie, Computer Networks: A Systems
Approach, 3rd ed., Morgan Kaufmann, 2003
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Course Overview (cont)
 Prerequisites: EETS 7301 or equivalent previous
exposure to data communications
 Introductory graduate core course (required for new
MS Telecom students)


Part 1: basic networking (LANs, packet switching, network
protocols, routing)

Part 2: IP/ICMP

Part 3: TCP/UDP

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Bottom-up approach to TCP/IP protocols, as preparation
for advanced EETS courses
Part 4: application protocols (HTTP, SMTP, SNMP, VOIP,
video over IP) and network security if time allows
Grading
EE 5304
Exam 1 (2/28)
30%
30%
Exam 2 (4/4)
30%
30%
Exam 3 (finals week)
40%
30%
Term paper*
optional
10%
*Due last day of class
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EETS 7304
Outline
Week 1
Course overview, protocol layers
Week 2
Data link layer, LANs
Week 3
LANs, bridges, packet switching
Week 4
Network protocols (ATM, X.25), IPv4
Week 5
IPv4, ICMP
Week 6
IPv6, IP routers
Week 7
IP routers (Exam1)
Week 8
MPLS
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Outline (cont)
Week 9
Routing protocols, RIP, OSPF
Week 10
(spring break)
Week 11
UDP, TCP (Good Friday 3/25)
Week 12
(Exam 2) TCP
Week 13
TCP, RTP
Week 14
Client-server, WWW, DNS
Week 15
SMTP, SNMP
Week 16
VOIP, video over IP, (network security?)
(Exam 3)
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Term Papers
 15-20 page term paper on any topic of personal
interest related to Internet protocols


A technical deep paper, not a broad survey
Evaluation criteria: timeliness, correctness, depth, well
referenced
 Or hands-on project


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Good source for ideas is lab book (Comer, Hands-on
Networking with Internet Technologies) accompanying the
textbook
Evaluation criteria: completeness, correctness, level of
difficulty, well documented
SMU Incomplete Grades Policy
An Incomplete (I) may be given if the majority of the course
requirements have been completed with passing grades but
for some justifiable reason, acceptable to the instructor, the
student has been unable to complete the full requirements of
the course. Before an (I) is given, the instructor should
stipulate, in writing, to the student the requirements and
completion date that are to be met and the grade that will be
given if the requirements are not met by the completion date.
The maximum period of time allowed to clear the
Incomplete grade is 12 months (except for graduate thesis
and dissertation courses). If the Incomplete grade is not
cleared by the date set by the instructor or by
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SMU Incomplete Grades Policy (cont)
the end of the 12-month deadline, the (I) may be changed to
an F or to another grade specified by the instructor. The
grade of (I) is not given in lieu of an F, WP, or other grade,
each of which is prescribed for other specific circumstances.
If the student's work is incomplete and the quality has not
been passing, an F will be given. The grade of (I) does not
authorize the student to attend the course during a later
semester. Graduation candidates must clear all Incompletes
prior to the deadline in the official University Calendar,
which may allow less time than 12 months. Failure to do so
can result in removal from the degree candidacy list.
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SMU Statement on Disability
Disability Accommodations: If you need academic
accommodations for a disability, you must first contact Ms.
Rebecca Marin, Coordinator, Services for Students with
Disabilities (214-768-4563), to verify the disability and to
establish eligibility for accommodations. Then you should
schedule an appointment with the professor to make
appropriate arrangements.
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SMU Statement on Religious Observance
Religiously observant students wishing to be absent on
holidays that require missing class should notify their
professors in writing at the beginning of the semester, and
should discuss with them, in advance, acceptable ways of
making up any work missed because of the absence.
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SMU Statement on Excused Absences
Students participating in an officially sanctioned, scheduled
University extracurricular activity will be given the
opportunity to make up class assignments or other graded
assignments missed as a result of their participation. It is the
responsibility of the student to make arrangements with the
instructor prior to any missed scheduled examination or
other missed assignment for making up the work.
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SMU Statement on Academic Honesty
Academic dishonesty may be defined broadly as a student'
misrepresentation of his or her academic work or of the
circumstances under which the work is done. This includes
plagiarism in all papers, projects, take-home exams, or any
other assignments in which the student represents work as
being his or her own. It also includes cheating on
examinations, unauthorized access to test materials, and
aiding another student to cheat or participate in an act of
academic dishonesty. Failure to prevent cheating by another
may be considered as participation in the dishonest act.
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SMU Honor Code
Intellectual integrity and academic honesty are fundamental
to the processes of learning and evaluating academic
performance; maintaining them is the responsibility of all
members of an educational institution. The inculcation of
personal standards of honesty and integrity is a goal of
education in all the disciplines of the University. The faculty
has the responsibility of encouraging and maintaining an
atmosphere of academic honesty by being certain that
students are aware of the value of it, that they understand the
regulations defining it, and that they know the penalties for
departing from it. The faculty should, as far as is reasonably
possible, assist students in avoiding the
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SMU Honor Code (cont)
temptation to cheat. Faculty must be aware that permitting
dishonesty is not open to personal choice. A professor or
instructor who is unwilling to act upon offenses is an
accessory with the student offender in deteriorating the
integrity of the University. Students must share the
responsibility for creating and maintaining an atmosphere of
honesty and integrity. Students should be aware that
personal experience in completing assigned work is essential
to learning. Permitting others to prepare their work, using
published or unpublished summaries as a substitute for
studying required materials, or giving or receiving
unauthorized assistance in the preparation of
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SMU Honor Code (cont)
work to be submitted are directly contrary to the honest
process of learning. Students who are aware that others in a
course are cheating or otherwise acting dishonestly have the
responsibility to inform the professor and/or bring an
accusation to the Honor Council. Students and faculty must
mutually share the knowledge that any dishonest practices
permitted will make it more difficult for the honest students
to be evaluated and graded fairly, and will damage the
integrity of the whole University. Students should recognize
that their own interest, and their integrity as individuals,
suffer if they condone dishonesty in others.
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Honor System
All undergraduate students at SMU are under the
jurisdiction of the Honor Code, and as such will be required
to sign a pledge to uphold the Honor Code. The Honor
Council is composed of 22 students appointed by the
Student Senate to represent the undergraduate schools and
classes of the University. The Council’s responsibility is to
maintain and promote academic honesty. Students are
required to warn or to report to the Honor Council or faculty
any student suspected of violating the Honor Code, and to
inform the instructor of a course in which violations are
suspected that he or she may not be achieving an atmosphere
conducive to academic honesty.
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Honor System (cont)
Suspected violations reported to the Honor Council by a
student or by an instructor will be investigated and, if the
evidence warrants it, a hearing will be held by a Board
composed of five members of the Honor Council. Suspected
cases of academic dishonesty may be either handled
privately by the appropriate faculty member in whose class
the alleged infraction occurred, or referred to the Honor
Council. Appeals of actions by the Honor Council shall be
submitted to the All-University Judicial Council in writing
no later than three class days after the hearing. Appeals of
actions taken by instructors independently of the Honor
Council may be made through the traditional academic
routes.
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Term Paper Topics - Suggestions
 VOIP

Motivations, problems with quality of service and
interworking with telephone network
 Differentiated services (diffserv)

Concepts of diffserv architecture versus intserv
 Web caching

Techniques for caching and difficulties
 Mobile IP

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Principles and limitations of mobile IP, and possible
solutions
Term Paper Topics (cont)
 Wireless LANs (IEEE 802.11)

Standards, security, new developments
 Spam filtering

Bayesian spam filters
 Denial of service attacks

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Distributed DoS attack tools, defenses
Types of networks, protocol layers, OSI reference
model, TCP/IP protocol suite
Tom Oh
Dept of Electrical Engineering
[email protected]
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Outline
 Types of networks
 History
 Standards

Text book (Comer): Pg: 59
 Terminology

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Text book (Comer): Appendix 1: Glossary of Networking
Terms and Abbreviations
Types of Networks
 Networks can be classified by
TO 1-17-06 p. 26

Size

Switching

Media

Speed

Network protocols

Types of services
Network Size
 PANs - private, room, shared medium (radio)
 LANs - private, building, shared medium, access
control protocol
 MANs - public, city/campus, shared medium
 WANs - public, state/nation, switched
 internets - various administrations, national or
worldwide, heterogeneous, routers/gateways
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Type of Switching
 Distribution - one-way broadcast/multicast, no
contention

broadcast TV, CATV
 Shared medium - broadcast, medium access control
(MAC)

LANs, MANs
 Switched
TO 1-17-06 p. 28

Circuit switched, eg, telephone

Packet switched, eg, Internet
Media
 Twisted pair - 2 insulated copper wires, reduced
crosstalk, low rates < 56 kbps, eg, telephone local
loop
 Coax cable - copper core in conductive sheath, high
rate < 400 Mbps, low noise eg, LANs, CATV
 Optic fiber - glass or plastic, very low noise, very
high rate ~ Gbps, eg, telephone trunks, LANs, MANs
 Radio - possible interference, spectrum allocated by
FCC
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Speed
 Narrowband - generally 1.5 Mbps or slower
 Broadband - generally above 1.5 Mbps
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Network protocols
 Bluetooth (personal area)
 Ethernet, token ring, FDDI (local area)
 Gigabit ethernet, DQDB (metropolitan areas)
 X.25, ATM, frame relay (wide area)
 IP (internets)
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Services/Traffic
 Voice - telephony
 Video - television
 Data - LANs, Internet
 Integrated services - Internet, ATM
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Historical Highlights
 1820s telegraphy


Hans Oersted discovers EM changes carried over a wire
connected to battery, detected by compass
Samuel Morse invents repeaters and Morse code
 1854 Philip Reise, 1876 Alexander Bell, Eliza Gray invent telephone

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Bell founds Bell Telephone Co, buys Western Electric,
becomes AT&T
Historical Highlights (cont)
 1960s modems

Modulate digital data into voiceband analog signal,
allowing use of extensive telephone network

V.32 standard 9.6 kbps, V.32bis standard 14.4 kbps, V.34
standard 28.8 kbps, K56flex/V.90 standards 56 kbps
 1960s-1970s conversion of telephone network to
digital
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
1960s T-carrier digital transmission

1970s digital electronic programmable switches
Historical Highlights (cont)
 1969 ARPAnet
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
Advanced Research Projects Agency (now DARPA) of
DoD

Pioneered use of packet switching between military and
research centers

Inspired MILNET, TYMNET, TELENET, DECnet, and other
packet networks in 1970s

Restricted to military and academic users
Historical Highlights (cont)
 1970s LANs

Ethernet - Metcalfe at Xerox PARC
•
Simple, cheap local area networking

Token bus - GM

Token ring - IBM
 1974 IBM consolidates its network protocols into
Systems Network Architecture (SNA)

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Eventually basis for OSI layered model, adopted by ISO
in 1983
Historical Highlights (cont)
 1974 development of TCP/IP suite in ARPAnet
allowed for internetworking with other networks and
scalability

1982 mandated by DoD for internetworking
 1976 CCITT standard for X.25 public packet switched
networks
 1970s ISDN standards

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Allows high speed digital connectivity through telephone
network
Historical Highlights (cont)
 1970s-1980s fiber optics


Optic fibers and laser diodes improve in cost and
performance
Deployed extensively in telephone network and LANs
 1970s-1980s research demonstrates viability of
packet switching for voice and video
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
Led to 1988 ATM standard for broadband ISDN

ATM gains popularity for private networks
Historical Highlights (cont)
 1983 ARPAnet split into research ARPAnet and
military MILNET
 1980s new NSFNET high-speed backbone
 1986 FDDI standard for dual ring fiber optic LANs
 1990 DQDB standard for IEEE 802.6 MAN
 1992 Internet opened to commercial traffic
 1993 Mosaic web browser (later Netscape)
 1995 US Internet opened to commercial ISPs
 1998 Google founded
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Standards
 Standards are important because of cooperative
nature of networking

Example of standards process: ATM cell size
 International Telecommunications Union (ITU)


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Agency of UN for international recommendations on radio,
telephony, data
ITU-T, formerly CCITT, in charge of telephony, telegraphy,
data, eg., X.25, ISDN, ATM
Standards (cont)
 International Standards Organization (ISO)

Voluntary group of national standards organizations,
covering various topics

Divided into technical committees and working groups

OSI reference model
 American National Standards Institute (ANSI)
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
US representative in ISO and ITU

Led standards in frame relay, SONET
Standards (cont)
 Institute of Electrical and Electronics Engineers
(IEEE)

Largest professional organization

802 standards for LANs and MANs
 Internet Architecture Board (IAB), formerly Internet
Activities Board


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Oversees Internet Research Task Force (long term
research) and Internet Engineering Task Force (near term
engineering)
IETF (www.ietf,org) sets Internet “standards”
Standards (cont)
 Federal Communications Commission (FCC)

Spectrum allocation, tariffs on interstate traffic
 Public utilities commissions
 Post, telegraph and telephone (PTTs)
 Vendor forums

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ATM Forum, ADSL Forum, Frame Relay Forum
Terminology
 User = host, end system, subscriber, station, or
application that communicates over a network or
subnetwork
 Link = physical medium for transmitting a bitstream
between hosts and nodes
 Nodes = switches, routers, multiplexers,
concentrators, crossconnects, network elements
 Network = links + nodes usually with same protocol
suite
 internet = interconnection of possibly
heterogeneous networks
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Terminology (cont)
 Network topology = physical layout

Bus, ring, star, tree, mesh
 Packet switching

Store-and-forward method of relaying messages between
switches, like postal mail

Packets = header + payload (data)

Packet headers have well defined fields
header
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payload (data)
Terminology (cont)
 Protocols = set of rules for communication between
user-user, user-network, and node-node

Define specific use of header/trailer fields

Typically complex → reduce problem by layering
 Layered protocols
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
Easier to understand, design, and change

Network architecture = suite of protocol layers
Terminology (cont)
 Network design


Given costs and demand, optimize topology, resources,
and protocols
Trade-off between costs and network performance →
operations research
 Provisioning


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Forecast long-term traffic from past demand
Deploy additional facilities where needed to meet
projected demand
Terminology (cont)
 Performance analysis


Apply modeling and analysis to understand behavior of
traffic (eg., delays, loss) and protocols
Usually probabilistic (queueing theory) or simulation
 Network management (operations, administration,
maintenance)


Monitor, configure, and troubleshoot network to maintain
proper operation of facilities
Generally high level, mostly manual, and not real-time
•
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E.g., fault detection, isolation, recovery
Terminology (cont)
 Traffic control

Algorithms to control traffic to avoid or reduce network
congestion
•

At the same time, use network resources (buffers,
bandwidth) efficiently by resource sharing
•
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More real-time and automated than network management
E.g., connection admission control, congestion notification
IBM's Systems Network Architecture (SNA)
 1974 IBM's proprietary protocol suite for
communications between IBM mainframes and other
machines

One of first examples of layered protocols, major
influence on OSI model
 Seven protocol layers:
Layer 7: Transaction services

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Applications communicate with each other
SNA (cont)
Layer 6: Presentation services

Ensures that data is delivered in appropriate format

Compression/decompression
Layer 5: Data flow control
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
Recovers lost or errored data

Handles how packet are acknowledged

Handles temporary halt/restart of transmissions
SNA (cont)
Layer 4: Transmission control



Establish, maintain and terminate sessions between
nodes
Ensure that messages arrive at destinations correctly and
sequentially
Encryption/decryption
Layer 3: Path control

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Provides logical connections between hosts with specific
addresses
SNA (cont)

3 sublayers: (links make up channels, channels
make up transmission groups)
•
Transmission group control: manage all links between two nodes
•
Explicit route control: finds route between two nodes
•
Virtual route control: manages logical connection between two nodes
 2. Data link control

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Responsible for reliable point-to-point transmission across
physical medium
SNA (cont)
SNA allows for various choices: synchronous data
link control (SDLC), X.25 layer 2, logical link control
(LLC)
1. Physical control


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Physical signal and interfaces, e.g., electrical, optical,
radio
OSI Protocol Reference Model
 1983 International Standards Organization (ISO)
standards to promote interconnection of different
computer networks with Open System
Interconnection (OSI) reference model

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Based largely on SNA
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