This material was developed with funding from the
National Science Foundation under Grant # DUE 1601612
OSI Model
OSI Model
Next
Restart
Back
Click on the Next button to continue.
This layer integrates network functionality into the operating system and enables communication across the network between clients and servers. Network services associated with this layer include HTTP, Telnet, FTP, TFTP and SNMP. The Application layer does not include specific applications, instead, it provides the capability for services to operate on the network.
Application Layer
Presentation Layer
Session Layer
Transport Layer
Network Layer
Data Link Layer
Physical Layer
The Session Layer manages the sessions in which data are transferred. Functions include management of multiple sessions, assignment of a session ID to keep data streams separate and the setup, maintenance, and teardown of communication sessions.
Click on the next layer for more information.
The Presentation Layer formats/presents data the Application layer can accept. Examples include ASCII, GIF, JPEG, MPEG. It is also responsible for formatting, decrypting and uncompressing data so that it can be received by the Application Layer.
The Transport Layer provides a transition between the upper and lower layers of the OSI model. Transport layer functions include end-to-end flow control, port and socket numbers, segmentation, sequencing, and combination and connection services - for either reliable (connection-oriented) or unreliable (connectionless) delivery of data. Transport layer protocols include TCP (connection-oriented) and UDP (connectionless). Data at the Transport layer is referred to as segments.
The Network Layer responds to requests from the Transport Layer and issues requests to the Data Link Layer. The network layer is responsible for packet forwarding through routers. Functions include identifying hosts and networks by using logical or IP addresses, maintaining a list of known networks and neighboring routers, and determining the next network point where data should be sent. At the Network layer, data segments are called packets.
The Data Link layer defines the rules and procedures for hosts as they access the Physical layer, including how devices are identified by a unique hardware or MAC address, how and when devices have access to the LAN and can transmit, how to verify that the data received from the Physical layer is error free (parity and CRC) and flow control - how devices control the rate of data transmission. Data segments are called frames. Devices at this layer include switches, bridges and NICs.
The Physical layer of the OSI model sets standards for sending and receiving electrical signals between devices. The Physical layer identifies how digital data (bits) are converted to electric pulses, radio waves, or pulses of light and moved across network cables. Data segments are called bits. NICs, repeaters, hubs and modems operate in this layer.
The Physical layer of the OSI model sets standards for sending and receiving electrical signals between devices. The Physical layer identifies how digital data (bits) are converted to electric pulses, radio waves, or pulses of light and moved across network cables. Data segments are called bits. NICs, repeaters, hubs and modems operate in this layer.
The Data Link layer defines the rules and procedures for hosts as they access the Physical layer, including how devices are identified by a unique hardware or MAC address, how and when devices have access to the LAN and can transmit, how to verify that the data received from the Physical layer is error free (parity and CRC) and flow control - how devices control the rate of data transmission. Data segments are called frames. Devices at this layer include switches, bridges and NICs.
The Network Layer responds to requests from the Transport Layer and issues requests to the Data Link Layer. The network layer is responsible for packet forwarding through routers. Functions include identifying hosts and networks by using logical or IP addresses, maintaining a list of known networks and neighboring routers, and determining the next network point where data should be sent. At the Network layer, data segments are called packets.
The Transport Layer provides a transition between the upper and lower layers of the OSI model. Transport layer functions include end-to-end flow control, port and socket numbers, segmentation, sequencing, and combination and connection services - for either reliable (connection-oriented) or unreliable (connectionless) delivery of data. Transport layer protocols include TCP (connection-oriented) and UDP (connectionless). Data at the Transport layer is referred to as segments.
The Session Layer manages the sessions in which data are transferred. Functions include management of multiple sessions, assignment of a session ID to keep data streams separate and the setup, maintenance, and teardown of communication sessions.
The Presentation Layer formats/presents data the destination system can accept. Examples include ASCII, GIF, JPEG, MPEG. It also formats, encrypts and compresses data so that it can be sent across the network.
This layer integrates network functionality into the operating system and enables communication across the network between clients and servers. Network services associated with this layer include HTTP, Telnet, FTP, TFTP and SNMP.
The Open Systems Interconnection (OSI) model describes a networking framework and how information from a software application in one computer moves through a network to a software application in another computer. In this example we show a web page moving from one computer to another.
http://www.
The Open Systems Interconnection model (OSI model) provides a standardized way for various telecommunication and computer systems to work with each other. Each of the seven layers works with the layer above it supporting transmission using standard protocols.