1. Dr. Clincy Professor of CS
CS 4622 Computer Networks
Dr. Clincy
Professor of CS
High Level Course Description:
Will learn how the Internet works – not just the edges of the network, but also the core of the network. ALL of the info and knowledge shared in this course is CURRENT and USEFUL today. We will learn about addressing, routing … we will learn about how routers and switches work --- we will master IPv4 and also be introduced to IPv6. If you are leaning towards a networking or network-security type career, this course will be key.
The prerequisite for CS4622 was recently removed from CS3501 with no replacement – will need to cover the prerequisite in this course (scientific fundamentals versus applied) (i.e. like you did in CS3501 as it relates to computers)
As a result of the above bullet item, no group project and some CS4622 topics will not be covered
Dr. Clincy
Intro and Lecture

2. Kick Off
Behrouz Forouzan, Data Communications & Networking 4th Edition (handouts provided)
Dr. Clincy
Intro and Lecture

3. Tentative Course Outline: Subject to Change
General Topic & Exam Coverage
Lecture Coverage
Chapters (in order)
Exam 1 – Data Communications Fundamentals and Theory:
An introduction to the theory and fundamentals of data communications at the physical layer more so. Topics include: data encoding & decoding, signaling, transmission, communication media, multiplexing, and the OSI reference model.
1 through 8
Handouts 1 - 5
Exam 2 - Overview of Underlying Technologies:
Critical networking concepts; RFC’s; the importance of standards; underlying network technologies (LANs, Point-to-Point WANs, Switched WANs); Intro of TCP/IP reference model & protocol layering
9 through 13
1, 2, and 3
Exam 3 - Addressing Issues:
IP, Internet addresses (classful and classless), subnetting and supernetting, ARP; RARP; BOOTP; DHCP; DNS, NAT, etc..
14 through 20
7, 5, 8, 18 and 19
Exam 4 - Network Layer Protocols:
Router functionality, dynamic versus static routing, routing tables, unicast routing (RIP, BGP, OSPF), routing algorithms (link state, distance vector)
21 through 23
4, 6 and 11
Exam 4 – Multicast Routing
multicasting, routing algorithm (path vector), multicast routing protocols (MOSPF, DVMRP, CBT, PIM), MBONE, End-to-end datagram delivery, and Flow control
23 and 24 12
Exam 4 – Transport Layer Protocols, Next Generation IP
UDP and TCP, IPv6, transitioning from IPv4 to IPv6
25 and 26
14, 15, 26, and 27
Dr. Clincy
Intro and Lecture

4. Tentative Course Schedule: Subject to Change
Explain how the remainder lectures can be completed online
Explain Lecture 26 makeup for Jan 8th
Dr. Clincy
Intro and Lecture

5. Assessment
will curve GRADES if the SCORE AVERAGE is lower than 70 (curving vs bell-curve approach, TCP/IP new topic) (give example of curving concept – next bullet)
No make-up exams – last exam will count for missed exam – can miss only 1 exam
If last exam is missed, replaced with the average of the first three exams
Dr. Clincy
Intro and Lecture

6. Lesson in Stats – Example of Curving Grades – Raw Score to Final Grade
What is an Avg ?
What is the SD ?
This is the curve
Fitting raw scores to a curve
? = 90 + (RS-77)/1.4
? = 80 + (RS-63)/1.4
? = 70 + (RS-49)/1.4
? = 60 + (RS-35)/1.4
Dr. Clincy
Intro and Lecture

7. General Policies and Expectations:
Attendance at all classes is highly encouraged but NOT required. Concepts and ideas discussed in one class are used as building blocks for more concepts and ideas in the next class.
Any class session missed by the student is the student's responsibility to make up.
Makeup exams will NOT be given; instead, the last exam will count in place of the missed exam. If last exam missed, replaced with average of other exams.
Exams should be returned to the Professor in class right after the review for the student to receive a grade. Grades are not logged until the students have reviewed the exams for grading mistakes. If students take the exam from the classroom, a grading penalty of 50% will be used due to the fact the Professor has no real way of determining if the exam was tampered with or not.
Project assignments MUST be turned in on time to receive full credit. Late project assignments will be graded severely – for each day the assignment is late, the assignment’s grade will be reduced by 20%.
Students will not be allowed to makeup missed project assignments.
It’s hard to teach a subject like TCP/IP from a single source. The Professor will use multiple sources to teach various concepts – multiple sources such as (1) text book, (2) lecture notes, (3) handouts, (4) URL’s, and (5) project assignments. Every topic detail WILL NOT necessarily be found in the our text.
Students are expected to read the text and any other supporting documentation the Professor distributes.
Dr. Clincy
Intro and Lecture

8. General Policies and Expectations:
In being successful in this subject, expect a minimum of 2-3 hours of study per hour of lecture (6-9 hours per week)
The Professor expects students to take advantage of office hours when needing clarification or help.
The Professor greatly supports students sending s at any time – it will be the goal of the Professor to reply to s within a 24-hour time span (not counting weekends).
Be sure and provide the Professor a functioning personal address for you (on your Sign-up List) – already has KSU address
Lecture notes purpose: serve as a guide to the Professor – help organize and time lecture
Guarantee: current lecture notes will be posted before the next up-and-coming lecture (ie. lecture notes 1 will be posted before lecture 2 occurs)
See syllabus for withdrawal policy, enrollment policy, and the Academic Integrity Statement. Be sure and give me the signed copy at the next class meeting
Go to my website for a syllabus and lecture notes
Dr. Clincy
Intro and Lecture

9. Chapter 2 (handout 1– only sections 2.1, 2.2 and 2.3)
Dr. Clincy
Professor of CS
Dr. Clincy
Intro and Lecture

10. Open Systems Interconnection (OSI) Reference Model
Why Study OSI?
An excellent model for conceptualizing and understanding data communications
More granularity in functionality - more functional delineation
Key points:
Modular
Hierarchical (chain of command, pecking order)
Boundaries between layers (called interfaces)
NOTE: the protocols or functionality with in the layer could change however, the interface remains the same – this facilitates the flexibility
Dr. Clincy
Intro and Lecture

11. Advantages of Layering
Easier application development
Network can change without all programs being modified
Breaks complex tasks into subtasks
Each layer handles a specific subset of tasks
Communication occurs
between different layers on the same node or stack (INTERFACES)
between similar layers on different nodes or stacks (PEER-TO-PEER PROCESSES)
Dr. Clincy
Intro and Lecture

12. OSI’s Layered Approach Example
Network A
Network B
Actual commands invoked, presentation
Top Layer
Some Intermediate Layer
Bottom Layer
Top Layer
Some Intermediate Layer
Bottom Layer
Facilitate the actual communications
Network interfaces, raw bits
How does peer-to-peer communication work ?
Dr. Clincy
Intro and Lecture

13. OSI Application Open Systems Interconnection Presentation Session
Transport
Network
Data Link
Physical
Open Systems Interconnection
Developed by ISO
(International Organization for Standardization)
Contains seven layers
Dr. Clincy
Intro and Lecture

14. OSI’s Layered Approach
between different layers on the same node or stack (INTERFACE)
between similar layers on different nodes or stacks (PEER-TO-PEER PROCESSES)
Dr. Clincy
Intro and Lecture

15. OSI Reference Model ? Bottom 3 layers (Data Comm Layers) Top 4 layers
Responsible for getting data or info to destination
Routing and switching occurs
Define the electrical and physical standards
Performs bit ordering, transmission of the bits, and error detecting and correcting
Top 4 layers
Creation and interpretation of the data
Protocols for data formatting, message syntax, dialogue management, message sequences and info presentation are used
Dr. Clincy
Intro and Lecture

16. OSI Physical Layer (Old CS3501)
Responsible for transmission of bits
Always implemented through hardware
Encompasses mechanical, electrical, and functional interfaces
Encoding and Decoding issues: how 0’s and 1’s are converted to signals
Signal translation (ie. electrical to optical)
Signal Multiplexing and Demultiplexing
Signal Modulation and Demodulation
Transport medium: Coaxial, Twisted Pair, Optical, etc..
Transmission Rate/Data Rate – how fast to send bits
Transmission mode: transmission direction (simplex, duplex)
Physical Topology: network layout
Dr. Clincy
Intro and Lecture

17. OSI Data Link Layer (partially Old CS3501 and CS4622)
Responsible for error-free, reliable transmission of data
Framing, Flow control, Error control (detection/correction), Access Methods
Makes use of physical address because with in the same network
Network Layer
Data Link Layer
Physical Layer
Actually sends the packets (groups of frames) from node to node using a routing algorithm
Takes raw data (bits) and transform them into frames, error control, etc.
Transmit and receive the raw data (bits)
Dr. Clincy
Intro and Lecture

18. OSI Network Layer (CS4622)
Responsible for routing of messages through networks
Concerned with type of switching used (circuit v. packet)
Handles routing among different networks
NOTE: with in the same network, only the DATA LINK layer is needed – amongst multiple networks, the NETWORK LAYER is needed
No need for routing with in the same network (LAN)
Routing across “internetworks”
Makes use of logical address vs physical address because not with in the same network
Dr. Clincy
Intro and Lecture

19. OSI Network Layer (CS4622)
Dr. Clincy
Intro and Lecture