1.1 Explain concepts related to the Open System Interconnection (OSI) reference model.

What is Layer 1 responsible for?

• The physical connection between devices, including the transmission and reception of raw bit streams over a physical medium such as cables and wireless signals.

Key Aspects of Layer 1

• Physical Media: The cables and connectors used to connect devices

• Hardware Devices: Network interface cards (NICs), hubs, repeaters, and modems

Anything related to the physical components and their role in transmitting data is?

• a part of Layer 1

Layer 2 - Data Link Layer

• formats messages into data frames and adds headers with destination and source MAC addresses.

Data Link layer uses

• MAC addresses to identify devices on the same local network.

Logical Link Control (LLC)

• Identifies Network layer protocols and encapsulates them, handles flow control, and sequencing.

What is the main responsibility of the Data Link layer?

• The Data Link layer handles the physical transmission of data, error notification, network topology, and flow control.

What is the role of MAC addresses at the Data Link layer?

• MAC addresses uniquely identify devices on a local network for proper data delivery.

What are the two sublayers of the Data Link layer?

• The two sublayers are Media Access Control (MAC) and Logical Link Control (LLC).

Responsibilities of Layer 3

• Logical Device Addressing: Assigning addresses to devices so they can be identified on the network.

• Determining the Best Path: Finding the best route to send data from one device to another.

Protocols like RIP, EIGRP, and OSPF ?

• help routers communicate and update each other about network paths.

What is the main responsibility of the Network layer?

• The Network layer is responsible for logical device addressing, tracking device locations, and determining the best way to move data between devices.

What device operates at the Network layer and provides routing services?

• Routers operate at the Network layer and provide routing services.

Layer 4 - Transport Layer

• Provides end-to-end data transport services, establishing a logical connection between sending and receiving hosts.

• Handles the segmentation and reassembly of data for end-to-end communication between hosts

Layer 4 - Protocols Used

• It uses protocols like TCP for reliable communication and UDP for faster, unreliable communication

What are the two main protocols used at the Transport layer, and how do they differ?

• TCP is reliable and connection-oriented, using acknowledgments, sequencing, and flow control, while UDP is faster, connectionless, and does not guarantee delivery.

Layer 5 - Session Layer

• sets up, manages, and tears down sessions between presentation layer entities.

• coordinates communication between systems

The session layer keeps data?

• from different applications separate, allowing multiple sessions, like multiple browser tabs, to function independently

Why is data separation important at the Session layer?

• Data separation ensures that an application's data remains separate from other applications' data, allowing multiple sessions to run independently.

Layer 6 - Presentation focus

• Takes data from one system, changes it into a common format that all systems understand, and then sends it off.

Layer 6 Role and Function:

• Responsible for data translation and code formatting.

The Application layer

• is where users interact with the computer

Layer 7 - Application Layer Responsibilities:

• Identifies and establishes communication partners.

• Supports activities like file transfers, email, remote access, network management, and client-server processes.

How do applications like Google Chrome interact with the Application layer?

• Applications like Chrome use Application layer protocols, such as HTTPS or FTP, to interact with remote resources

Do applications like Microsoft Word reside in the Application layer?

• No, applications like Microsoft Word do not reside in the Application layer