Can you explain RDT versions with FSMs?

Sure, I'd be happy to explain RDT versions with FSMs!

RDT (Reliable Data Transfer) is a protocol used in computer networks to ensure that data is transmitted reliably from one device to another. There are several versions of RDT, each with its own set of features and capabilities. One way to implement RDT is using Finite State Machines (FSMs).

An FSM is a mathematical model used to represent complex systems that change over time. In the context of networking, an FSM can be used to model the behavior of the sender and receiver in a network communication.

The simplest version of RDT is RDT 1.0. In this version, the sender simply sends the data to the receiver without any error checking or correction. The receiver accepts the data as it is, without checking for errors. This version of RDT is not reliable, as it cannot detect or correct errors.

RDT 2.0 adds error detection to the protocol. In this version, the sender adds a checksum to the data it sends, which allows the receiver to check for errors. If the checksum does not match, the receiver requests that the sender retransmit the data.

RDT 3.0 adds error correction to the protocol. In addition to the checksum, the sender adds redundancy to the data it sends, allowing the receiver to correct errors. If the receiver detects an error, it can use the redundant data to correct it.

Each version of RDT can be implemented using an FSM. The FSM for RDT 1.0 is very simple, with just two states: send and receive. The sender sends the data, and the receiver receives it. There is no error checking or correction.

The FSM for RDT 2.0 is more complex, with additional states for error detection and retransmission. When an error is detected, the receiver enters a state where it requests that the sender retransmit the data.

The FSM for RDT 3.0 is even more complex, with additional states for error correction. When an error is detected, the receiver enters a state where it attempts to correct the error using the redundant data sent by the sender.

In summary, RDT is a protocol that ensures reliable transmission of data in computer networks. Each version of RDT can be implemented using an FSM, which models the behavior of the sender and receiver in the network communication.