This is a Java-based network simulator for Assignment 2 (COMP211). The project simulates packet transmission using an event-driven approach and includes implementations for sender and receiver protocols.

• Assign2code.iml — provided by instructor
• Assignment2.java — provided by instructor (main entry)
• Event.java — provided by instructor
• EventList.java — provided by instructor
• Message.java — provided by instructor
• NetworkHost.java — provided by instructor
• NetworkSimulator.java — provided by instructor
• Packet.java — provided by instructor
• Receiver.java — implemented as part of this assignment (student work)
• Sender.java — implemented as part of this assignment (student work)
• Testing.java — test code (part of the project)

• Java JDK 8 or higher
• Recommended IDE: IntelliJ IDEA (Windows)

1. Open the project in IntelliJ IDEA.
2. Compile and run Assignment2.java.

• gobackn — Implements the Go-Back-N protocol. The sender can transmit multiple packets within a window and uses cumulative acknowledgments. On timeout of a packet, the sender retransmits all unacknowledged packets starting from the base sequence number. Suitable for higher throughput.

• stopandwait — Implements the Stop-and-Wait protocol. The sender transmits one packet at a time and waits for its acknowledgment (or timeout) before sending the next. Simpler but lower throughput.

Switch branches with:

• git checkout gobackn
• git checkout stopandwait

• Receiver.java and Sender.java are the parts implemented by the student; other source files were provided by the instructor.
• This assignment received a score of 98/100.