What is the Open Systems Interconnection model (OSI model)?

Map Of Internet 1973

About

This page is about the Open Systems Interconnection (OSI) model that describes layers for data transmission.

Element

The elements of each layer are:

Layers

The level 5 (session) and 6 (presentation) are nowadays implemented in the level 7 (application) and above

Level Name Data unit name Data Unit example Description Protocol
7 Application layer Message Message Higher level (Resource Sharing, Remote file access, …) HTTP, SMTP, FTP, DHCP, DNS, Telnet, SNMP, …
6 Presentation layer Message Message Data Translation (Character encoding, data compression and encryption/decryption) MIME, XDR, ASN.1, ASCII, PGP
5 Session layer Message Message Session functionality Named pipe, NetBIOS, SAP, PPTP, RTP, SOCKS, SPDY, X.225
4 Transport layer Packet Segment Packet
Datagram Packet
Data transmission between network points TCP, UDP, SCTP, DCCP, SPX
3 Network layer Packet IP Packet Addressing, routing and traffic control IP Protocol, ICMP, IPsec, IGMP, IPX, IS-IS, Apple Talk, X.25, PLP
2 Data link layer Packet Frame Frames transmission between two physical nodes connected ATM, ARP, …
1 Physical layer Bit Bit, Symbol Raw bit transmission over a physical medium IEEE 802.3 (Ethernet cable), IEEE 802.11 (Wifi), USB, Bluetooth, Rs232 (modem, printer, …)





Discover More
Card Puncher Data Processing
Code design - (Connection|Session)

During the use of a product, a session or connection is a execution context that holds identification data (if any) and group actions (such as interaction or transaction) that take place within...
Map Of Internet 1973
Data link layer (OSI level 2)

This page is the Data link layer OSI level 2 LAN technologies like: Ethernet, TokenRing, FDDI, Dialup connections line PPP SLIP links.
Map Of Internet 1973
NetWork

Maps of the Internet in 1973 This section groups all articles over networking. In the internet age, all networks may be considered as subnet. To transmit data between two hosts in one network,...
Map Of Internet 1973
What is the Application layer, level 7 of the OSI model?

What is the Application layer, level 7 of the OSI model? Application layer is the 7 layer of OSI model that contains all services/application that implements a functionality above the transport layer...
Map Of Internet 1973
Network - Data unit

A buffer in Networking is called a data unit. When data is sent across a network, it is sent as thousands of small chunks called data unit, so that many different users can download the same data at the...
Ethernet Cables
Network - Ethernet

Ethernet is a LAN technology part of the Data link layer (OSI level 2) that creates ethernet packet known as frame that are carried out physically by ethernet cables. TCP/IP sends a TCP packet known...
Map Of Internet 1973
Network - Firewall

The firewall analyzes network traffic and decides whether to ACCEPT or DROP IP packets. At this layer we are talking : packets and port numbers not applications or sockets. OS
Map Of Internet 1973
Network - Remote Transfer Application Protocols / Remote File Access (Http, Ftp, Scp, )

Network - Remote Transfer Application Protocols / Remote File Access (Http, Ftp, Scp, ) ... This page is applications that implements a protocol to transfer/transport data: from a remote services...
Network Simple Route
Network - Route

If you want to use TCP/IP to send a data packet, the network layer (in the OSI layer model or the IP layer) must determine if and how the target IP address can be accessed. The routing information...
Map Of Internet 1973
Network - transport layer

The transport layer is the 4 layer in the OSI model and is the following data unit: segment (TCP) datagram (UDP) They just transport bits from one host to another. In this layer, the protocol...



Share this page:
Follow us:
Task Runner