It has a vertical set of layers, each having different functions. It follows a bottom-up approach to transfer the data. It is robust and flexible, but not tangible. The main intent of OSI reference model is to conduct the designing and development of the digital communication hardware, devices and software in a way that they can efficiently interoperate.
In contrast, the OSI model is just a conceptual framework to interpret how applications communicate over a network. An interviewer asks mostly that question. You provide a useful matter to people. Thanks for sharing this article with me and whole people. Splendid work. I am very pleased and it is of a great help to me.
Thank you and Big ups for the good work. It can also provide explicit flow control function. The network layer handles packet routing via logical addressing and switching functions. A network is a medium to which many nodes can be connected.
Every node has an address. When a node needs to transfer message to other nodes, it can merely provide the content of the massage and the address of the destination node, then the network will find the way to deliver the message to the destination node, possibly routing through other nodes.
If the message is too long, the network may split it into several segments at one node, sending them separately and reassembling the fragments at another node.
The data link layer provides node-to-node transfer—a link between two directly connected nodes. It handles packaging and unpacking the data in frames. It defines the protocol to establish and terminate a connection between two physically connected devices, such as Point-to-Point Protocol PPP.
The data link layer is generally divided into two sublayers—media access control MAC layer and logical link control LLC layer. MAC layer is responsible for controlling how devices in a network gain access to a media and permission to transmit data.
LLC layer is responsible for identifying and encapsulating network layer protocols, and controls error checking and frame synchronization. The physical layer defines the electrical and physical specifications of the data connection. For example, the layout of pins of the connector, the operation voltages of an electrical cable, optical fiber cable specifications, and the frequency for wireless devices. It is responsible for transmission and reception of unstructured raw data in a physical medium.
Bit rate control is done at the physical layer. It is the layer of low-level networking equipment and is never concerned with protocols or other higher-layer items. Another name for it is Internet protocol suite. The transport layer, also known as the host-to-host transport layer, is responsible for providing the application layer with session and datagram communication services. TCP provides a one-to-one, connection-oriented, reliable communications service.
It is responsible for sequencing and acknowledgment of packets sent, and recovery of packets lost in transmission. UDP provides one-to-one or one-to-many, connectionless, unreliable communications service. UDP is used typically when the amount of data to be transferred is small such as that data would fit into a single packet. The Internet layer is responsible for host addressing, packaging, and routing functions.
The datalink layer is the point-to-point connection that transmits the data to the network layer. In the network layer, the data gets its address and routing instructions in preparation for its journey across the network. In the transport layer, the data hops between different points on the network on its way to its destination.
The session layer has a connection that manages the sessions happening between applications. The presentation layer is where data gets encrypted and decrypted and converted into a form that is accessible by the application layer, Application. In the application layer, an application, such as an internet browser, gets the data and a user can then interact with it.
Understanding how both models compare can help you decide which one works for your needs. How Fortinet Can Help. Quick Links. Online Demo Explore key features and capabilities, and experience user interfaces. Resource Center Download from a wide range of educational material and documents. Free Trials Test our products and solutions. Contact Sales Have a question?
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