Stream of Knowledge

 When learning about networking, one of the most critical layers to understand in the OSI Model is the Transport Layer (Layer 4) . This layer acts as a bridge between the applications you use daily (Layer 7) and the network infrastructure that actually delivers data (Layers 1–3). Two major protocols dominate this layer: TCP (Transmission Control Protocol) – reliable, connection-oriented. UDP (User Datagram Protocol) – fast, connectionless. The Transport Layer. In this guide, we’ll explore the Transport Layer in the OSI model , break down the TCP and UDP headers , and explain why this layer is so important for both network engineers (CCNA, CCNP, CCIE prep) and everyday internet users. 🔹 What is the Transport Layer (Layer 4 of the OSI Model)? The Transport Layer is responsible for end-to-end communication between applications running on different devices across a network. It ensures that: Data gets delivered to the correct application using port numbers . Data ...

  In this lesson, we explain   what the OSI model is   in an easy and understandable language. It is one of the most important concepts in networking, so we break it down into pieces to help you understand exactly what its purpose is. What is data encapsulation? To understand the OSI model, you must first understand what data encapsulation is. Let's explore the following example. Imagine you want  to send a letter to a friend  who lives in another city to invite him to your wedding. What if you send the letter without an envelope, with any information, such as the sender's and recipient's names, addresses, and postcodes? What if you simply write the letter and drop it in the mailbox at the post office?  Most readers of this CCNA course are so young that  they've never sent a physical letter in their lives . They live in the digital age and have grown up with emails and instant text messages. However, surprisingly, everyone understands the concept of th...