The OSI Reference Model layers, in order from top to bottomD. Appl.pdf
- 1. The OSI Reference Model layers, in order from top to bottom D. Application, Presentation, Session, Transport, Network, Data Link, Physical 1. Application Layer topmost layer of the OSI reference model, is the application layer. This layer directly support user applications, like software for file transfers, database access, and e-mail. It serves as a window through which application processes can access network services. 2.Presentation Layer It defines the format used to exchange data among networked computers. It is a network's translator. When dissimilar systems want to communicate, certain translation and byte reordering is done. It translates data from the format from the application layer into a recognized format. At the receiving computer, this layer translates intermediary format into format that can be useful to that computer's application layer. 3. Session Layer It allows two applications on different computers to open, use, and close a connection called a session. It performs name-recognition and other functions, such as security, that are needed to allow two applications to communicate over the network. 4. Transport Layer It provides an additional connection level beneath the session layer. It ensures that packets are delivered error free, in sequence, and without losses or duplications. At the sending computer, this layer repackages messages, dividing long messages into several packets and collecting small packets together in one package. T 5. Network Layer It is responsible for addressing messages and translating logical addresses and names into physical addresses. This layer also determines the route from the source to the destination computer. It determines which path the data should take based on network conditions 6. Data-Link Layer It sends data frames from the network layer to the physical layer. It controls the electrical impulses that enter and leave the network cable. On the receiving end, the data-link layer packages raw bits from the physical layer into data frames. 7. Physical Layer This layer transmits the unstructured, raw bit stream over a physical medium (such as the network cable). The physical layer is totally hardware-oriented and deals with all aspects of establishing and maintaining a physical link between communicating computers. The physical layer also carries the signals that transmit data generated by each of the higher layers.
- 2. Solution The OSI Reference Model layers, in order from top to bottom D. Application, Presentation, Session, Transport, Network, Data Link, Physical 1. Application Layer topmost layer of the OSI reference model, is the application layer. This layer directly support user applications, like software for file transfers, database access, and e-mail. It serves as a window through which application processes can access network services. 2.Presentation Layer It defines the format used to exchange data among networked computers. It is a network's translator. When dissimilar systems want to communicate, certain translation and byte reordering is done. It translates data from the format from the application layer into a recognized format. At the receiving computer, this layer translates intermediary format into format that can be useful to that computer's application layer. 3. Session Layer It allows two applications on different computers to open, use, and close a connection called a session. It performs name-recognition and other functions, such as security, that are needed to allow two applications to communicate over the network. 4. Transport Layer It provides an additional connection level beneath the session layer. It ensures that packets are delivered error free, in sequence, and without losses or duplications. At the sending computer, this layer repackages messages, dividing long messages into several packets and collecting small packets together in one package. T 5. Network Layer It is responsible for addressing messages and translating logical addresses and names into physical addresses. This layer also determines the route from the source to the destination computer. It determines which path the data should take based on network conditions 6. Data-Link Layer It sends data frames from the network layer to the physical layer. It controls the electrical impulses that enter and leave the network cable. On the receiving end, the data-link layer packages raw bits from the physical layer into data frames. 7. Physical Layer This layer transmits the unstructured, raw bit stream over a physical medium (such as the network cable). The physical layer is totally hardware-oriented and deals with all aspects of establishing and maintaining a physical link between communicating computers. The physical layer also carries the signals that transmit data generated by each of the higher layers.