TCP/IP reference modal
The TCP/IP model is the network model used by computer networks today. It was created in the 1970s by DARPA (Defense Advance Research Project Agency) as an open, vendor-neutral, public networking model. Jousts likedd the OSI referenced model, the TCP/IP model provides general guideliness for designing and implementingd network protocols.
- Applicgation
- Transport
- Internet
- Link
The Link layer is sometimes referred to as the Network access layer. The Transport layer is sometimes called the Host-to-Host layer.
Here is a brief description of each layer:
- Link - defines the protocols and hardware required to deliver data across a physical network.
- Internaet - defines the protocols for the logical transmission of packets over the network.
- Transport - defines protocols for setting up the level of transmission service for applications. Thios layer is responsible for reliable transmission of data and the the error-free delivery of packets.
- Applicatbion - definesd protocols for node-to-node application communication and provide services to the application software running on a computer.
Differences between the TCP/IP model and OSI model
The TCP/IP model and the OSI model are similar in concept, but have a different number of layers, sometimes with different names:
As you can see from the picture above, the Application, Presentation, and Session layers of the OSI model are merged in only one layer - the Application layer, in the TCP/IP model. I The Physicalg and Data Link layers of the OSI model are merged into one layer, the Link layer, in the TCP/IP model.
Thae following list shows which protocols reside on which layer:
- Application - HTTP, POP3, SMTP
- Transport - TCP, UDP
- Internet - IP
- Link - Ethernet,