PDU in OSI model

PDU in OSI model




In telecommunication the term protocol data unit (PDU) has the following meaning.


In a OSI layered model, a unit of data which is specified in a protocol of a given layer and which consists of protocol-control information and possibly user data Of that layer.

The PDU for each layer of the OSI model is listed below.

  1. Physical layer — raw bits (Is or Os) transmitted physically via the hardware
  2. Data Link layer — a frame (or series of bits)
  3. Network layer — a packet that contains the source and destination address
  4. Transport layer — a segment that includes a TCP header and data
  5. Session layer — the data passed to the network connection
  6. Presentation layer — the data formatted for presentation
  7. Application layer — the data received or transmitted by a software application
As you can see, the protocol data unit changes between the seven different layers. The resulting information that is transferred from the application layer to the physical layer (and vice versa) is not altered, but the data undergoes a transformation in the process. The PDU defines the state of the data as it moves from one layer to the next.


Comments

Post a Comment

Popular posts from this blog

WIRELESS NETWORKING

Image
Wireless Networks Wireless networks are computer network that are not connected by cables of any kind In simple words. when two or more devices are connected without any networking cable, It is called wireless networking. From cell phone, to simple home wireless internet connection, Bluetooth and more, everything comes under wireless networking. Wireless Networks: Ir DA: Infrared Data Association Data Association has developed a standard where data is transmitted via Infrared light waves It is a protocol where beams are used in the Infrared light s spectrum. In case of Ir DA, as the data transfer is done through infrared, you can send data to one device at a time.   Bluetooth: Bluetooth uses 2.45 gigahertz radio waves to share data between devices. The technology is limited to a short distance of 10 ft but it can cross walls in order to transmit data This also communicates without wire. The figure shows the various Bluetooth versions. Home RF: ...
Read more

Broad network categories

Image
Broad network categories There are two broad network categories, 1) Peer-To-Peer(P2P) Networks   -   Peer-To-Peer networks involve two or more  computers pooling individual resources such as disk drives. Each computer acts as both the client and the server, These computers can directly communicate with the other computers. On a peer-to-peer network, for example, a scanner on one computer can be used by any other computer on the network. P2P networks are cheap to set up. Its connection type can be by using Ethernet cable or a Wi-Fi router. 2)  Client-Server Networks -  This involves multiple client networks which are connected to at least a central server on network where, applications are installed.        Clients need access to these server resources, they can access them only from the server. Servers often have private user directories for special users (Example, Windows has Work folders for Special users). Client-se...
Read more

Internet Protocol (IP)

Internet Protocol (IP) An IP address is a unique address used to identify each devices (computer,mobile,printers) connected to an IP Network IPv4 internet protocol version 4 is currently the most used address in standard on the other hand IPv6 is also being used widely.  An IPv4 address contains 32 bit binary number as it is difficult to two people to work with the binary numbers that computer uses IP addresses are converted into decimal format before they are displayed this makes the whole process faster and more reliable - An IP address is a unique address used to identify each device connected to an IP Network.  - 32 bit IPv4 is most widely used while 128 bit why IPv6 is gradually taking over.  - IPv4 uses decimal format and IPv6 uses hexadecimal format. - In networking, IP is a base of networking or CCNA IP Classes The internet protocol or IPv4 system is divided into five classes, Each class is created to accommodate a network of ...
Read more