UNIVERSITY OF WEST ATTICA
SCHOOL OF ENGINEERING
DEPARTMENT OF COMPUTER ENGINEERING AND INFORMATICS
Computer Networks II
Vasileios Evangelos Athanasiou
Student ID: 19390005
Supervisor: Rania Garofalaki, Laboratory Teaching Staff
Athens, June 2022
The project involves a technical examination of TCP behavior through a series of structured questions based on a real network trace.
The analysis focuses on the TCP three-way handshake and the subsequent data transfer phase between a client PC and a web server.
| Section | Folder / File | Description |
|---|---|---|
| 1 | assign/ |
Assignment material |
| 1.1 | assign/Askisi6_TCP.pdf |
Assignment description in English |
| 1.2 | assign/Άσκηση6_TCP.pdf |
Assignment description in Greek |
| 2 | docs/ |
Project documentation |
| 2.1 | docs/Transmission_Protocol_System.pdf |
TCP protocol analysis and operation (English) |
| 2.2 | docs/Σύστημα_Πρωτοκόλλου_Μετάδοσης.pdf |
TCP protocol analysis and operation (Greek) |
| 3 | README.md |
Repository overview and usage instructions |
-
Client PC
- IP Address:
192.168.1.102 - TCP Port:
1161
- IP Address:
-
Server
- IP Address:
128.119.245.12 - Hostname:
gaia.cd.umass.edu - TCP Port:
80
- IP Address:
The report identifies and analyzes the three TCP segments used to establish a reliable connection:
-
SYN Segment
Initiated by the client with a relative Sequence Number = 0.
The SYN flag is set, indicating a request to establish a connection. -
SYN–ACK Segment
Sent by the server in response to the client’s SYN.- Sequence Number:
0 - Acknowledgment Number:
1(calculated as0 + 1, acknowledging the client’s SYN)
- Sequence Number:
-
ACK Segment
The final segment of the handshake, where the client acknowledges the server’s SYN–ACK and completes the connection setup.
-
TCP Flags
Detailed analysis of flags such as SYN, ACK, PSH, and others to determine the role and purpose of each segment. -
Sequence Management
Tracking of both relative and raw sequence numbers throughout the TCP session to understand data ordering and reliability. -
HTTP Integration
Identification of an HTTP POST command encapsulated within the TCP stream.
The POST request appears in the 4th TCP segment with a sequence number of 1, demonstrating the interaction between the transport and application layers.
-
Question 1
Analysis of the initial connection request (SYN segment). -
Question 2
Examination of the server’s response (SYN–ACK) and the acknowledgment mechanism. -
Question 3
Identification of specific application-layer commands (HTTP POST) within transport-layer TCP segments.
This laboratory analysis provides a clear and structured understanding of how TCP establishes reliable connections and transports application-layer data.
By examining real packet traces, the report highlights the interaction between TCP mechanisms and HTTP communication, reinforcing key concepts of transport-layer networking.
This project is a theoretical and analytical laboratory assignment based on the study of an existing TCP network trace.
No software compilation or network simulation is required.
- PDF Reader
- Any modern PDF viewer (Adobe Acrobat Reader, browser-based PDF viewer, etc.)
- Text Editor (Optional)
- For reviewing notes or annotations (VS Code, Notepad++, etc.)
- Windows
- Linux
- macOS
No packet capture tools (e.g., Wireshark) are required to run this project, as the analysis is already completed and documented.
git clone https://github.com/Computer-Networks-2/TCP.gitAlternatively, download the repository as a ZIP file and extract it locally.
After cloning or extracting the repository, the directory structure is as follows:
assign/
docs/
README.md- Navigate to the docs/ directory
- Open the report corresponding to your preferred language:
- English:
Transmission_Protocol_System.pdf - Greek:
Σύστημα_Πρωτοκόλλου_Μετάδοσης.pdf
- English: