Understanding network communication - Phase 2 - TCP IP model

TCP IP Model

TCP model introduced prior to OSI model.

Besides this, OSI model is just a reference model

Application Layer (Application Layer + Presentation  Layer + Session Layer)

Transport Layer 

Internet Layer (Network Layer)

Network Access (Data link Layer + Physical Layer )

• Application Layer
• HTTP[s], DNS,  DHCP, FTP
• Representing the data to user, encoding, compression
• Transport Layer
• TCP UDP
• Process to process communication
• Internet Layer 
• IPv4, IPv6
• Determines the best path via Routing
• Routing
• Network Access Layer
• Data into signal, carry over to media, read it back from media.
• PPP (point to point), Frame Relay, Ethernet

PDP - Stands for "Protocol Data Unit." A PDU is a specific block of information transferred over a network. It is often used in reference to the OSI model, since it describes the different types of data that are transferred from each layer.

• Application Layer
• In Application layer, PDU is Data 
• The data which is actually being transmitted by the application
• Transport Layer
• PDU here is Segment
• Internet Layer 
• PDU here is Packet
• Network Access Layer
• PDU here is Frame
• Physical Layer
• PDU here is bits