The internet model of network architecture, also known as TCP/IP reference model, was developed much earlier then the OSI reference model. It was developed from the US department of Defence’s (DoD) research network the ARPANET.
Eventually the ARPANET connected many universities and other government organizations. During the process of interconnecting all these through the exising telephone lines, satellite link and therefore, a new architecture was needed to overcome that. The architecture thus came out became known as the INTERNET or TCP/IP reference Model. The model has four layers normally.
1. The Host-to-Network Layer.
2. The Internet Layer.
3. The transport Layer.
4. The application Layer.