FTP (File Transfer Protocol) and TCP (Transmission Control Protocol) are both essential components of network communication but serve different purposes. FTP is an application protocol for transferring files, while TCP is a transport protocol that provides reliable data delivery between networks. (Reference: The Difference Between FTP and TCP)
Here's a breakdown of their key differences:
Key Differences Between FTP and TCP
| Feature | FTP (File Transfer Protocol) | TCP (Transmission Control Protocol) |
|---|---|---|
| Purpose | File transfer between a client and a server | Reliable data exchange between two applications on a network |
| Layer | Application Layer | Transport Layer |
| Functionality | Commands for file manipulation (upload, download, delete) | Provides connection-oriented, ordered, and error-checked data delivery |
| Connection | Requires two TCP connections (control and data) | Establishes a single connection for data transmission |
| Reliability | Relies on TCP for reliable data transfer | Inherently reliable, ensures data arrives in the correct order |
FTP Explained
FTP is specifically designed for transferring files. It operates at the application layer and uses TCP to establish two connections:
- Control Connection (Port 21): Used for sending commands and receiving responses. For example, commands to list files, change directories, or initiate a file transfer.
- Data Connection (Port 20 or dynamically assigned): Used for the actual transfer of file data. This connection is established separately from the control connection.
FTP can operate in two modes:
- Active Mode: The client opens a port and listens, and the server connects to it to establish the data connection.
- Passive Mode: The server opens a port and the client connects to it to establish the data connection. This mode is often preferred when clients are behind firewalls.
TCP Explained
TCP provides reliable, ordered, and error-checked delivery of data between applications. It operates at the transport layer and ensures that data is delivered correctly and in the correct sequence.
Key features of TCP:
- Connection-Oriented: Establishes a connection before data transfer.
- Reliable: Guarantees data delivery. If packets are lost, TCP retransmits them.
- Ordered: Ensures data arrives in the same order it was sent.
- Error-Checked: Detects and corrects errors during transmission.
Analogy
Think of TCP as the postal service. It provides the infrastructure to reliably deliver packages (data) from one place to another. FTP is like a specific service offered by the postal service, such as package delivery, with its own specific rules and procedures for handling files.
