• Known as Transmission Control Protocol or Internet Protocol
• Developed by ARPANET
• Support client-server and peer-to-peer

1. Physical Layer

• Responsible for carrying individual bits in a frame across the link
• Communication between two devices at physical later is logical because there is another hidden layer

2. Data-link Layer

• It is responsible for taking the datagram and moving across the link

3. Network Layer

• Responsible for creating a connection between the source computer and the destination computer
• It is a host-to-host communication

4. Transport Layer

• It is end-to-end
• Source host gets the message from the application layer; encapsulates it in a transport-layer packer (called a segment or a user datagram); and sends it through the logical (imaginary) connection, to the transport layer at the destination host

5. Application Layer

• Logical connection between the two application layers is end-to-end
• The two applications exchange messages as though they have a bridge between them