Differences between TCP/IP and OSI Models
TCP and IP mainly define the protocols used for the internet. On the other hand, other non-internet protocols like the Internetwork Packet Exchange (IPX) and the Datagram Delivery Protocol (DDP) also communicate with the OSI model (layer 3). Moreover, while TCP may function somewhat like layer 5 in the OSI model, it does not perform all the tasks involved in the process, such as authentication and authorization.Web Hosting Services
In general, TCP/IP will not make any assumptions about what is going on above the level of any given network session, which is level 5 in the OSI model. Similarly, TCP/IP will allocate all higher factors of network uses to the applications whereas the OSI model will assign two additional layers of standardized functions to it.
Therefore, when an application needs specific functions that are not provided by TCP/IP, it will have to supply the features on its own. Yet in the case of the OSI model, it assumes that no application will implement any functionality that belongs to the defined network layer. Likewise, TCP/IP will not state what is going on below the network layer.
Although IP assumes the presence of a network access layer, it does not define it. However, the OSI model will break the functions of the network access layer into two more defined layers – the physical layer and the data link layer – to perform the required tasks.