Department of Computer Science

C Sc 255 - Computer Networks, Fall 2004 (TR 12-1:15p; RVR 1002)

INSTRUCTOR:     Isaac Ghansah

Office: RVR (ECS)-4004; Phone:278-7659; Email: ghansah@csus.edu ;

WWW: http://gaia.ecs.csus.edu/~ghansahi/ ;

Office Hours: M 11a-12p, W 5p-7p; or by appointment


Computer networking fundamentals with emphasis on higher level protocols and functions. Course contents include network design considerations, software design and layering concepts, interface design, routing and congestion control algorithms, internetworking, transport protocol design, end-to-end communication, session and application protocols. Specific examples of commercial and international standards are cited.

Prerequisite: C Sc/CPE 138/175, or C Sc 205, or permission of instructor.

NOTE: The department now has a policy requiring every student in every course to provide transcripts showing proof that they have appropriate prerequisites. This requirement also makes sure that the new repeat policy is enforced. Every student must provide this documentation in order to be permitted to enroll in this course. It is the responsibility of the student to provide such documentation by providing a transcript with the said prerequisites highlighted.


1.      Peterson, L. and Davie, B., Computer Networks: Systems Approach, 3 Ed 2003 Morgan-Kaufmann (required)


2.      Ghansah I., C Sc 255 Class Notes, 2004, Online (required)


3.      Comer, D., Internetworking with TCP/IP, Vols. I, II, III  Prentice-Hall  (recommended)


1.      Stevens, W., TCP/IP Illustrated, Vols 1, 2, & 3, 1996, Addison Wesley

2.      Tanenbaum, A.,Computer Networks, 4ed., 2003, Prentice-Hall, Inc. 

3.      Stallings, W., Data and Computer Communications, 7ed., 2004 Prentice-Hall

4.      Leon-Garcia, A. and Widjaja, I., Communication Networks, 2Ed 2004, McGraw Hill

5.      Stallings, W., High Speed Networks and Internets, 2Ed 2002 Prentice Hall

6.      Hassan, M., Jain, R, High Performance TCP/IP Networking, 2004, Pearson Prentice Hall

7.      Research papers


1. To provide the student with understanding of Higher Level Protocols and Functions of Computer Networks especially TCP/IP Architecture and companion protocols.

2. To provide depth of knowledge of commercially available wide area networks.

3. To develop proficiency in access and use of current literature in the area.


Prerequisites by Topic:


1. The ISO OSI 7-layer model

2. Data communications of the physical and data link layers

3. Packet, Circuit and Message Switching.


Expected Learning Outcomes:

At the end of this course you should be able to:

  1. Explain the service provided by IP to upper layers and the specific functions performed to provide the service
  2. Explain the service provided by TCP to upper layers and the specific functions performed to provide the service
  3.  Identify different methods that can be used to implement congestion control at both the network and transport (TCP) layers.
  4. Calculate performance measures for error and flow control protocols.
  5. Calculate performance measures of routing algorithms and TCP protocol.
  6. Analyze and estimate performance measures of IP fragmentation over multiple networks.
  7. Differentiate between IPv4 and IPv6 in detail.
  8. Distinguish between IP companion protocols such as ICMP, ARP, RARP, BOOTP, DHCP
  9. Know the details of TCP including its limitations and how to improve on those limitations.
  10. Understand IP and its design concepts including fragmentation and re-assembly.
  11. Distinguish between the switching schemes: virtual circuit, datagrams, cell switching; their advantages and disadvantages; and how they are implemented.
  12. Distinguish between routing algorithms that are used in the Network Layer.

13.  Understand IP Tunneling and its purpose.

14.  Understand MPLS, its purpose and advantages.

  1. Understand all the issues involved with designing transport layer (i.e. flow control, error control, connection management, etc.)including timers and quantification of performance.
  2. Understand quality of service and security issues of the networks.
  3. Demonstrate knowledge of high performance issues of TCP/IP Protocols, and the Internet in general.


            Midterm                                                                     25%

            Final                                                                            40%

            Assignments                                                               10%

            Project/Oral and Written Communication                      20%

Attendance to Oral Presentations                           5%


Grading Breakdown (%):

A = 93-100                  C = 73-76

A- = 90-92                  C- = 70-72

B+ = 87-89                  D+ = 67-69

B = 83-86                    D = 63-66

B- = 80-82                  D- = 60-62

C+ = 77-79                  F = 59 or below


1.   Late assignment/project will be penalized by 20% if one lecture late.

Nothing will be accepted if more than one lecture late.

2.   Make-up exams will only be given under extreme circumstances. The instructor reserves the right to reject make-up requests.

3.   Attendance will not be taken after first week of classes. However, you are responsible for material presented and announcements made in class.

4.   Be aware of the school’s policy on drops, incomplete, repeats, and cheating (Academic Dishonesty).

5.  Discussion among students in assignments and projects is part of the  educational process and is encouraged. No discussion among students is allowed in any exams/quizzes. However, each student must make an effort to do his/her own work in all assignments and exams. No type of plagiarism will be tolerated except in the case of group work. In that case each student should indicate the part of the work which was his/her major responsibility in their final joint submission. Nevertheless, any work  submitted is a contractual obligation that the work is the student’s and for which he/she could be quizzed in detail. Any type of cheating which is brought to the attention of the instructor will be handled by the Dean of Students. The computer science department now has a comprehensive cheating policy. Please check the department’s website www.ecs.csus.edu/csc . In addition, unless otherwise stated, the use of the following devices during exams/quizzes is prohibited: cell phones, pagers,  laptops, and PDAs.  I WILL GIVE YOU A FORM WHICH YOU MUST SIGN INDICATING THAT YOU HAVE READ AND UNDERSTOOD THESE POLICIES (INCLUDING THE ONE AT THE WEBSITE) BEFORE YOU CAN TAKE THIS COURSE.



There are a lot of reading assignments. You should endeavor to read the assigned pages before coming to class. There will also be homework assignments to be handed in. In addition, you will be required to complete an independent project, which is worth a considerable fraction of your grade for the course.

The class notes are online and should be considered as a guide. Many parts of it are not detailed enough to be self-contained. In addition, experience shows that new material is added every semester. Therefore, attendance to class is necessary in order to understand the details.


Independent student projects involving programming (ie. simulation or implementation), or research paper. A list of possible projects are provided by the instructor. Students may choose their own topics upon approval of instructor. Joint programming projects are encouraged. Oral and written communication skills are essential  for any work environment you find yourself. Thererefor, the deliverables for the Projects will include a detailed report and oral presentation report and/or demonstration  The grading will you’re your written and oral communication skills.  For details of the specific grading criteria see details of Independent Project call for proposals.



a) Mailing List

I have established a Mailing List for this course. It is MANDATORY for every student accepted into the course to subscribe to the Mailing List within the first two weeks of classes. The list will be used to facilitate electronic communication for the course. Failure to subscribe to the list in a timely manner could result in your missing important assignments, clarifications, announcements, etc that are sent by email. The instructor will not be held responsible for your failures.


b) Assignment/Homework Submission

You must submit all homework/assignments/project reports electronically as an  email attachment. I will not accept a hardcopy. The attached file should be a Word document and must have a name according to one of the following formats (depending on the type of assignment).  Your email should be sent to the lab instructor or grader (if one is assigned) with copy to me. If no grader is assigned for the course email your submission to me.

Student-name_255_hmwk_homework#, student-name_255_lab_lab#, student-name_255_project_project#


For example if a student named John Doe is submitting homework#1 the file name of the email attachment should be



Please note: If the attachment is not according to proper format as stated above, it will not be accepted.








Introduction. Requirements. Layered Architectures. Packet and Circuit Switching. Tradeoffs.  Direct Link and Shared Networks. Hardware, Encoding, Errors, MAC Protocols, Wireless

Examples: HDLC, SONET, 802.3, FDDI, 802.11, etc



Ch. 1, 2


Packet Switching. Routing/Switching. Virtual Circuits and Datagrams.   Cell Switching (ATM). Bridges.


Ch. 3


Internetworking. Simple Internet. Routing. Global Internet. Addressing including masking and CIDR. IP, ARP, DHCP, ICMP, RIP, OSPF, BGP, IPv6, Mobile IP, etc



Ch. 4


End to end Protocols. Transport Protocols. Transport Layer Design Concepts. End-to-end flow control, error recovery, and connection management. Internet Transmission Control Protocol (TCP). Congestion Control. Performance. RPC

Ch. 5


Congestion Control. Resource Allocation. Application Issues. Examples: RED, DECbit, RSVP

Ch. 6.


Network Security concepts, including secure protocols, IPSec, VPNs etc.

Ch. 8


Application Layer Protocols –HTTP, DNS, etc.

Advanced topics as time permits – Peer-to-peer and Overlay networks.


Ch. 7, 9


Independent Project Presentations



Thanksgiving Recess: Nov.

FINAL EXAM SCHEDULE:Tu Dec 14, 12:45-2:45pm