Which OSI layer is responsible for data transfer from source to destination?
Whenever you connect two devices either on the same or different networks, a question may arise in your mind regarding the connectivity of the devices. The two devices may have different architecture and implement different protocols , then how can they connect and share information with each other. Show Actually, they need a standardized model that can be implemented by both to establish a connection between them. There are also some standardized protocols that they can implement to connect. So, In this blog, we will learn about a widely accepted standardized model, i.e., the OSI(Open System Interconnection) model. We will also learn the mechanism, how two devices are connected using this model. We'll also focus on the different layers of this model along with their functionalities. OSI ModelOSI model is a layered framework that allows communication between all types of the computer system. It has seven layers. OSI model is introduced by ISO(International Organization for Standardization) in 1984. Each layer has its own functionalities and calls upon the services of the layer just below it. These layers are a package of protocols that are implemented by computers to connect in the network. In other words, the OSI model defines and is used to understand how two computers connect with each other in a computer network. The seven layers of the OSI model, are as follows:
We will learn about these layers and their functionalities one by one. 1. Physical LayerThe Physical Layer is the lowest layer of the OSI model and it deals with data in the form of bits or signals. The type of signal being generated depends upon the transmission medium. For example, if we are using copper wire or LAN cable, the output signal will be an electrical signal. Likewise, the output signal will be a light signal for optical fibre cable, and radio signal for air as a transmission medium. At the sender's side, the physical layer will get the data from the upper layer and convert it into bitstreams(0's and 1's) and send it through a physical channel. At the receiver's side, it will convert the bitstreams into frames to be passed to the data-link layer. Following are the functionalities of a physical layer:
2. Data-Link LayerThe Data-Link Layer is the second layer of the OSI model. It performs the physical addressing of data. Physical addressing is the process of adding the physical(MAC) address to the data. MAC(Media Access Control) Address is a 48-bit alpha-numeric number that is embedded in NIC(Network Interface Card) by the manufacturer. In other words, the data-link layer is embedded as software in the NIC which provides a means for data transfer from one computer to another via a local media. Thus, the data-link layer facilitates the transmission of data within the same network only. The source and destination MAC addresses are included in the data header file by the data-link layer. At the sender's side, it receives the data in the form of packets from the network layer and converts it into smaller forms, called the data frame. At the receiver's side, it converts the data frame into packets for the network layer. Following are the main functionalities of a data-link layer:
3. Network LayerThe Network layer is the third layer of the OSI model. It mainly performs the transmission of data from one computer to another in different networks. This layer may not be so beneficial if we are transmitting the data in the same network. The network layer performs logical addressing(IP addressing) of the data. The source and destination IP addresses are included in the data header file by the network layer. The data is in the form of packets in this layer. At the sender side, the network layer breaks the data segments received from the upper layer into smaller units, called data packets. Similarly, at the receiver's side, it reassembles the data packets into segments for the upper layer, i.e., the transport layer. Routers are mainly used in the network layer for routing purposes. Some of the protocols that are mostly used in this layer are OSPF(Open Shortest Path First), BGP(Border Gateway Protocol), IS-IS(Intermediate System to Intermediate System), etc. Following are the main functionalities of a network layer:
4. Transport LayerThe Transport layer is the fourth layer of the OSI model. It is mainly responsible for the process-to-process delivery of the data. It performs flow and error control in the data for its proper transmission. The transport layer controls the reliability of communication through various functionalities. At the sender's side, the transport layer receives the data from the upper layer and performs segmentation. The source and destination port numbers are also included in the header file of the data before forwarding it to the network layer. At the receiver's side, the transport layer performs the reassembly and sequencing of data. It reads the port number of the data from the header file, and then direct it towards the proper application. Following are the main functionalities of a network layer:
5. Session LayerThe Session layer is the fifth layer of the OSI model. It mainly helps in setting up, closing and managing the connection in the network. Actually, whenever two devices get connected, a session is created, which is terminated as soon the connection is no longer required. The termination of the session is important to avoid the unnecessary wastage of resources. In other words, the session layer performs session management. The session layer enables the devices to send and receive the data by establishing connections and also terminates the connection after the data transfer. It mainly performs authentication and authorization for establishing a secure connection in the network. Following are the main functionalities of a session layer:
6. Presentation LayerThe Presentation layer is the sixth layer of the OSI model. It mainly performs data translation, encryption & decryption, and compression in the network. The presentation layer deals with the syntax and semantics of the information exchanged between two systems. At the sender's side, it receives the data from the application layer and performs data encryption and compression to it. At the receiver's side, it receives the data from the transport layer and performs data translation, decryption, and uncompresses data. Following are the main functionalities of a presentation layer:
7. Application LayerThe Application layer is the topmost layer of the OSI model. This layer is mostly used by the network applications, that use the network. It mainly acts as an interface between the user and the network services. The Application layer provides services for network applications with the help of protocols. Some of the most widely used application layer protocols are HTTP, HTTPS, FTP, NFS, DHCP, FMTP, SNMP, SMTP, Telnet, etc. Following are the main functionalities of an application layer:
This is all about the OSI model, its various layers and its functionalities. Hope you learned something new today. That's it for this blog. Which layer is responsible for transferring the data from source to destination?The network layer uses network addresses (typically Internet Protocol addresses) to route packets to a destination node. The data link layer establishes and terminates a connection between two physically-connected nodes on a network. It breaks up packets into frames and sends them from source to destination.
What OSI layer is responsible for moving the packets from source to the destination?Summary. Which OSI layer transfer data between networks?Layer 2 of The OSI Model: Data Link Layer provides the functional and procedural means to transfer data between network entities and to detect and possibly correct errors that may occur in the physical layer.
Which layers of the OSI model are called source to destination?Network OSI layer is responsible for source to destination delivery of packet.. The third layer of the seven layers of Open Systems Interconnection (OSI) network model is the Network layer. ... . Very Important Point: The transport layer is responsible for the process to process delivery of the entire message.. |