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The OSI model is a conceptual framework that describes how different computer systems can communicate over a network using standard protocols.
The OSI model divides the communication process into seven layers, each with a specific function and interface.
Physical layer: This layer is responsible for transmitting and receiving raw bits over a physical medium, such as a cable or a wireless channel. It defines the electrical, mechanical, and functional characteristics of the physical devices and interfaces. Some examples of protocols in this layer are Ethernet, Wi-Fi, Bluetooth, and USB.
Data link layer: This layer is responsible for providing reliable and error-free data transfer between adjacent nodes on a network. It also handles the access control and framing of data packets. Some examples of protocols in this layer are MAC, PPP, HDLC, and ARP.
Network layer: This layer is responsible for routing and forwarding data packets across different networks. It also handles the addressing and fragmentation of data packets. Some examples of protocols in this layer are IP, ICMP, IGMP, and RIP.
Transport layer: This layer is responsible for providing end-to-end data delivery and reliability between two nodes on a network. It also handles the flow control and congestion control of data packets. Some examples of protocols in this layer are TCP, UDP, SCTP, and DCCP.
Session layer: This layer is responsible for establishing, maintaining, and terminating sessions between two nodes on a network. It also handles the synchronization and coordination of data exchange. Some examples of protocols in this layer are RPC, NFS, SQL, and SIP.
Presentation layer: This layer is responsible for translating, encrypting, and compressing data between two nodes on a network. It also handles the formatting and representation of data. Some examples of protocols in this layer are SSL, TLS, JPEG, and MPEG.
Application layer: This layer is responsible for providing services and applications to the user. It also handles the user interface and communication with other applications. Some examples of protocols in this layer are HTTP, FTP, SMTP, and DNS.
TCP/IP stands for Transmission Control Protocol/Internet Protocol.
It is a set of rules and standards that govern how computers communicate over a network, such as the Internet.
TCP/IP is also called the Internet protocol suite, because it consists of many protocols that work together to enable data transmission across different networks and devices
The TCP/IP model is widely used in modern networking because it is flexible, scalable, interoperable, and robust
It allows different types of networks and devices to communicate with each other using common protocols and standards.
It also supports various applications and services that enable users to access information and resources on the Internet.
Network Interface Layer: The network interface layer is responsible for transmitting and receiving raw bits over a physical medium, such as a cable or wireless signal. It frames the packets from the internet layer into data units called frames, and adds information such as source and destination addresses, error detection and correction codes, and flow control. It also defines the electrical, mechanical, and functional characteristics of the physical devices and media. Some of the protocols in this layer are Ethernet, Wi-Fi, Bluetooth, etc
Internet Layer: The internet layer is responsible for routing data packets across multiple networks or subnetworks. It adds logical addresses, such as IP addresses, to the segments from the transport layer, and determines the best path to deliver the packets to their destination. It also handles congestion control and fragmentation of packets if needed. Some of the protocols in this layer are IP, ICMP, ARP, etc
Transport Layer: The transport layer is responsible for providing end-to-end data delivery between two applications on different hosts. It segments the data from the application layer into smaller units called segments, and adds information such as port numbers, sequence numbers, and checksums. It also provides services such as connection-oriented or connectionless communication, reliable or unreliable delivery, and flow control and error recovery. Some of the protocols in this layer are TCP, UDP, SCTP, etc
Application Layer: The application layer is the highest layer of the TCP/IP model. It provides various services and applications that allow users to access network resources, such as web browsers, email clients, file transfer programs, etc. The application layer interacts with the transport layer to send and receive data. Some of the protocols in this layer are HTTP, SMTP, FTP, DNS, etc
The OSI model is a conceptual and protocol-independent framework that describes how different computer systems can communicate over a network using standard protocols. The OSI model divides the communication process into seven layers, each with a specific function and interface. The OSI model was developed in 1984 by the International Organization for Standardization (ISO) as a reference model for understanding and designing the system architecture
The TCP/IP model is a practical and protocol-oriented standard that defines how computers communicate over a network, such as the Internet. The TCP/IP model consists of four layers, each with a specific function and interface. The TCP/IP model was designed by Vint Cerf and Bob Kahn in the 1970s as a standard protocol for every network, including the Internet
The OSI model and the TCP/IP model have different approaches to communication. The OSI model is vertically approached, meaning that each layer performs its task independently and passes the data to the next layer without any changes. The TCP/IP model is horizontally approached, meaning that each layer can access any data from any other layer and modify it as needed
The OSI model and the TCP/IP model have different levels of reliability and delivery. The OSI model guarantees the delivery of packets by the transport layer, which provides connection-oriented or connectionless services, reliable or unreliable delivery, and flow control and error recovery. The TCP/IP model does not guarantee the delivery of packets by the transport layer, which only provides connection-oriented or connectionless services, and leaves the reliability and delivery to the application layer
The OSI model and the TCP/IP model have different levels of flexibility and scalability. The OSI model is more flexible than the TCP/IP model, because it allows for the replacement of tools and changes in each layer without affecting the other layers. The TCP/IP model is less flexible than the OSI model, because it is difficult to replace or change the tools in each layer without affecting the other layers. However, the TCP/IP model is more scalable than the OSI model, because it supports various routing protocols and uses a client-server architecture that can accommodate many devices and networks