Also called the DoD model

There are 2 versions of the TCP/IP Model:

  • The 4 Layer one which is found in most of the IT related books (RF1122)
  • The 5 Layer one which is newer and was made to align more with the OSI model. The Network Interface Layer is split into Data Link and Physical Layer (Not defined as an standard but considered valid)

OSI Model Mapping to TCP IP Model

Layer 1: Network Interface

Consist of the physical medium that interconnect computers
Responsible for defining a common way of interpreting signals from the physical layer
It is responsible for Hop to Hop Communication

Physical Layer Concepts
Data Link Layer Concepts

Layer 2: Internet Layer

Responsible for End to End Communication
Get data across a collection of network (across nodes)
IP : Internet Protocol

Internet Layer Concepts

Layer 3: Transport Layer

Responsible for Server to Server Communication
TCP: Transmission Control Protocol (Reliable Data Transfer)
UDP: User Datagram Protocol (Unreliable Data Transfer)
RTP: Read Time Protocol (Video & Audio Transfer)

Transport Layer Concepts

Layer 4: Application Layer

The actual data generated by the source application is available at this layer

Application Layer Protocols