George Mason University
Course Description

CS455/555 Computer Communications and Networking

Sections 001 and 002 Fall 2007: M 19:20-22:00, ST Room 126

updated 31 Aug 07


Professor J. Mark Pullen
ST2 Room 403 (mail drop ST2-430)
Office hours 1600-1800 Monday and by appointment (including evenings/weekends)
Preferred contact is email:
Phone: 703-993-1538


The course will present techniques and systems for communication of data between computational devices and the layers of the Internet Protocol Suite. Topics include the role of various media and software components, local and wide area network protocols, network design, performance and cost considerations, and emerging advanced commercial technologies. Emphasis is on the TCP/IP family of protocols. The ISO 7-layer reference model to organize the study. Students will program simplified versions of the protocols as part of the course project.

Prerequisites: STAT344 or equivalent; ability to program in C/C++ or Java. Students will be required to confirm in writing that they meet the prerequisites.

Project: We will use the Network Workbench (NW), software developed at GMU that simulates a protocol stack and displays the results, using a text interface. Students will create modules for Internet stack layers and run them in the NW environment. NW will be available via IT&E computing labs in ST2 and by dial-in. A version that runs under Borland C++ Builder (version 5) and Microsoft Visual C++ (version 6) also is available. Well documented code must be submitted by email to the TA for grading via an upload webpage at Additional projects are available for extra credit. The CS555 TA is Muhammad Abdulla, email, office hours 17:00-19:00 Monday and 10:00-12:00 Thursday in 437 ST2. The TA also is available by appointment at other times (send email at least 24 hours in advance to set up appointment). Student problems with the project are to be addressed to the TA; if he cannot resolve your problem, he will pass it on to the author of NW who will deal with it.

The project is documented in one of the required texts. Copies of class slides, software and documentation for the project are included with this text on CDROM. Additional project information will be found at

New project software, the Java Network Workbench (JNW), will be introduced this semester on a voluntary basis. Send email to if you want to participate.

Students are responsible for assigned readings and all material outlined in lecture slides.


Homework 10%, Midterm exam 25%, Project 30%, Final exam 35%.

Project credit breakout: DLC2, DLC3, LAN1, WAN2, TRN1 and INT3 five points each; extra credit up to four of DLC1, LAN2, WAN3, WAN4, INT1, and INT2 two points each.

Missed exams must be arranged with the instructor BEFORE the exam date.

Assignments are due by 19:30 on assigned date. Late assignments lose 10% per class credit. No project submission will be accepted after the reading day.

All students are expected to abide by the Honor Code as stated in the GMU catalog and elaborated for Computer Science. Students should be aware that their submissions may be checked by plagiarism detection software.

Grading is proficiency-based (no curve), cutoffs will be in the vicinity of (but not higher than) A  93; A- 90; B+ 87; B 83; B- 80; C 70.

Extra credit is available by doing extra projects; however, no student who fails the final exam will receive a grade higher than C, regardless of extra credit earned.

GMU Academic Calendar    |    GMU Final Exam Schedule

SYLLABUS (subject to revision)
date and topic/readings in Peterson text/project assignment

8-27 Course introduction; network concepts; 7-layer and 5-layer models / Sections 1.1 to 1.4 / NW Setup introduced

9-3 Holiday; no class.

9-10 Physical layer: analog telecommunications / Section 1.5 / Project DLC2: CRC introduced NOTE: Due to NATO committee commitment of instructor, this session will be presented via Internet, with backup recorded lecture online

9-17 Physical layer: digital telecommunications / Sections 2.1 & 2.2

9-24 Data compression, security principles, integrity, appropriate use / Sections 2.3, 2.4 & 7.2 / Project DLC2 due

10-1 Data link control; discrete event simulation / Section 2.5 / Project DLC3: ARQ introduced

10-8 Mid-term exam; NOTE: Because of the Columbus day holiday, this is a Tuesday

10-15 Local area networks / Sections 2.6 to 2.9 / Project LAN1: CSMA/CD LAN introduced

10-22 Network Layer: WANs, X.25, routing / Chapter 3 except Section 3.3; Project DLC3 due

10-29 Internet Architecture (IPv4); Metcalfe’s Law /Chapter 4/ Project WAN 2: Forwarding and Optimization introduced; Project LAN1 due

11-5 Queueing basics; transport layer: TCP and UDP; IPv6 / Chapter 5 & Sections 6.1 to 6.4 / Project TRN1: Reliable Transport introduced

11-12 Multicast, multimedia and ATM networking /Section 6.5, 7.1 & 3.3 / Project INT3: Integrated Stack introduced; Project WAN2 due

11-19 Network Security and Network Management / Chapter 8 / Project TRN1 due; extra credit project LAN2 due

11-26 No class; work on project

12-3 Higher layer protocols / Chapter 9

12-10 reading day; Project INT3 due; all remaining extra credit projects due

12-17 Final exam (comprehensive) / all chapters listed above / Exam location TBA


Required textbook: Peterson & Davie: Computer Networks 4th Ed, Morgan Kaufmann, 2007
Required project book: Pullen, Understanding Internet Protocols, Wiley, 2000

References (available in library):
1. Comer, Internetworking with TCP/IP, Vol. I, 3rd Ed., Prentice-Hall, 1996
2. Tanenbaum, Computer Networks, 4th Ed., Prentice-Hall, 2002
3. Stallings, Data and Computer Networks 8th Ed. Prentice-Hall, 2006

Course communication: we will use email extensively. Students are responsible to read email daily. Announcements will be sent to the class email list, which consists of GMU email accounts. If you want to receive your class email at a different address, send email to the instructor requesting this.

Course notices and assignments will be provided via email. Course materials (for example, homework solutions) will be available though the course webpage, Students are responsible for assigned readings and all material outlined in lecture slides.

Internet-based course delivery: classes will be available on computer desktops at home or office by using dial-up through GMU Internet facilities. See All classes may be taken over the network, however students must appear in person for midterm and final exams.