Phase 1 Day 1

How many layers are in the TCP/IP model?

4 Layers

How many layers are in the OSI model?

7 Layers

OSI Application Layer

Provides the interface for application to access network services

OSI presentation layer

Responsible for data formatting, translation, encryption, and compression. Ensures data is in a format the application layer can use.

OSI Session Layer

Manages the connections (sessions) between application, establishing, maintaining, and terminating them.

OSI Transport layer

End-to-end communication and data integrity. Segments and reassembles data. Uses TCP (reliable, connection-oriented) and UDP (fast, connectionless).

OSI Network layer

Routing of data packets across different networks. Uses logical addressing (IP addresses) to determine the best path.

OSI Data Link layer

Handles node-to-node data transfer within the same network. Manages physical addressing (MAC addresses), framing, and error detection on the local link.

OSI Physical Layer

Defines the physical medium and electrical/optical/radio signals. Deals with raw bit stream transmission (cables, connectors, voltage levels).

TCP/IP Application layer

Combines OSI Layers 5, 6, & 7. Provides application support for the user, including data formatting, session management, and application-specific protocols (HTTP, SMTP, DNS)

TCP/IP Transport Layer

Corresponds to OSI Layer 4. Provides end-to-end data delivery, error correction, and flow control (TCP/UDP).

TCP/IP Internet Layer

Corresponds to OSI Layer 3. Responsible for logical addressing (IP) and routing packets across a network of networks (the internet).

Network Access

Combines OSI Layers 1 & 2. Deals with all the physical and logical link issues needed to send and receive data over the physical medium (Ethernet, Wi-Fi, etc.).

What is layer 1 of the OSI model?

Physical

What is layer 2 of the OSI model?

Data Link

What is layer 3 of the OSI model?

Network

What is layer 4 of the OSI model?

Transport

What is layer 5 of the OSI model?

Session

What is layer 6 of the OSI model?

Presentation

What is layer 7 of the OSI model?

Application

What is Layer 1 of the TCP/IP model?

Network Access

What is Layer 2 of the TCP/IP model?

Internet

What is Layer 3 of the TCP/IP model?

Transport

What is Layer 4 of the TCP/IP model?

Application