TCP/IP Model in Computer Network
What is TCP/IP Model in Computer Network
The TCP/IP model was developed prior to the OSI model. The TCP/IP model is not exactly similar to the OSI model. The TCP/IP model consists of five layers: the application layer, transport layer, network layer, data link layer and physical layer. The first four layers provide physical standards, network interface, internetworking, and transport functions that correspond to the first four layers of the OSI model and these four layers are represented in TCP/IP model by a single layer called the application layer. TCP/IP is a hierarchical protocol made up of interactive modules, and each of them provides specific functionality. Here, hierarchical means that each upper-layer protocol is supported by two or more lower-level protocols.
The TCP/IP model is a concise version of the OSI model. It contains four layers, unlike seven layers in the OSI model. The layers are;
- Process/Application Layer
- Host-to-Host/Transport Layer
- Internet Layer
- Network Access/Link Layer
Difference between TCP/IP and OSI Model
| TCP/IP | OSI Model |
|---|---|
| TCP refers to Transmission Control Protocol. | OSI refers to Open Systems Interconnection. |
| TCP/IP has 4 layers. | OSI has 7 layers. |
| TCP/IP is more reliable. | OSI is less reliable. |
| TCP/IP does not have very strict boundaries. | OSI has strict boundaries. |
| TCP/IP follow a horizontal approach. | OSI follows a vertical approach. |
| TCP/IP uses both session and presentation layer in the application layer itself. | OSI uses different session and presentation layers. |
| TCP/IP developed protocols then model. | OSI developed model then protocol. |
| Transport layer in TCP/IP does not provide assurance delivery of packets. | In OSI model, transport layer provides assurance delivery of packets. |
| TCP/IP model network layer only provides connection less services. | Connection less and connection oriented both services are provided by network layer in OSI model. |
| Protocols cannot be replaced easily in TCP/IP model. | While in OSI model, Protocols are better covered and is easy to replace with the change in technology. |
Network Access Layer
A network layer is the lowest layer of the TCP/IP model. A network layer is the combination of the Physical layer and Data Link layer defined in the OSI reference model. It defines how the data should be sent physically through the network. This layer is mainly responsible for the transmission of the data between two devices on the same network.
Internet Layer
An internet layer is the second layer of the TCP/IP model. An internet layer is also known as the network layer. The main responsibility of the internet layer is to send the packets from any network, and they arrive at the destination irrespective of the route they take.
Protocals Used in Internet Layer
- IP Protocol
- ARP Protocol
- ICMP Protocol
Transport layer
The transport layer establishes basic data channels that applications use for task-specific data exchange. The layer establishes host-to-host connectivity, meaning it provides end-to-end message transfer services that are independent of the structure of user data and the logistics of exchanging information for any particular specific purpose and independent of the underlying network.
Application layer
It is responsible for handling high-level protocols, issues of representation. The application layer includes the protocols used by most applications for providing user services or exchanging application data over the network connections established by the lower level protocols. This may include some basic network support services such as protocols for routing and host configuration. Examples of application layer protocols include the Hypertext Transfer Protocol (HTTP), the File Transfer Protocol (FTP), the Simple Mail Transfer Protocol (SMTP), and the Dynamic Host Configuration Protocol (DHCP).
Protocals Used in Application Layer
- HTTP Protocol
- SNMP Protocol
- SMTP Protocol
- DNS Protocol
- TELNET Protocol
- FTP Protocol