TCP/IP and OSI Architecture Similarities & Difference

ISO-OSI Architecture has following layers:

1. Physical Layer
2. Data Link Layer
3. Network Layer
4. Transport Layer
5. Session Layer
6. Presentation Layer
7. Application Layer

TCP/IP Architecture has following layers:

1. Host to Network Layer
2. Internet Layer
3. Transport Layer
4. Application Layer

Similarities between TCP/IP & OSI Architecture:

• Both models are based on concept of "Stack of Independent Protocols"
• All the layers from bottom till Transport Layer provides End to End Transport Service
• All the layers above the Transport Layer are application oriented and use the Transport Service

Difference between TCP/IP & OSI Architecture:

• The protocols in ISO are better hidden and can be replaced relatively easily as technology changes
• OSI supports both connectionless and connection oriented communication in network layer but only connection oriented communication in the transport layer. TCP/IP supports only connectionless communication in the network layer and both connectionless and connection oriented communication in the transport layer
• The ISO model has 7 layers whereas the TCP/IP model is composed of 4 layers
• The TCP/IP the protocol cam first and the model was made based on the protocol. ISO-OSI the model was devised before the protocols were inverted