Скачать или смотреть Computer Networks | Lecture 3

To Make Two Networks with Different Solutions Communicate
All People Seem To Need Data Processing

OSI Model (Open Systems Interconnection):

1. Application Layer:
Sends requests to make a connection using protocols.

2. Presentation Layer:
Syntax
Compression
Encryption
Translation

3. Session Layer:
Establishes, manages, and terminates sessions between devices.

4. Transport Layer:
Segmentation
Flow Control
Error Control
Works between different networks.

5. Network Layer:
Packet Routing
Logical Addressing (IP)
Path Determination

6. Data Link Layer:
Frame Handling
Flow Control
Works within the same network.

7. Physical Layer:
Transmission of bits over the physical medium (cables, radio waves, etc.)

TCP/IP Protocol Suite:

1. Application Layer:
Provides network services to applications such as web browsers and email clients.
Protocols: HTTP, HTTPS, FTP, SMTP, DNS, SSH, etc.

2. Transport Layer:
Ensures reliable data delivery and error checking.
Protocols: TCP (Transmission Control Protocol), UDP (User Datagram Protocol)

3. Internet Layer:
Handles addressing, routing, and packet forwarding between devices.
Protocols: IP, ICMP, ARP, etc.

4. Network Access Layer (Link Layer):
Deals with the physical transmission of data over the network medium.
Includes Ethernet, Wi-Fi, and hardware addressing (MAC addresses).

Summary:
OSI Model = Conceptual guide.
TCP/IP = Real-world implementation.
Together, they explain how data travels across networks.