| A | B |
|---|
| OSI Model | Open System Interconnection Model |
| application layer | layer closes to the user. Provides services to user applications. Ex. browsers |
| presentation layer | common data format. |
| session layer | regulates communication between hosts. Provides services to the presentation layer. |
| transport layer | reliable service, transport error detection-and-recovery and information flow control. |
| network layer | path selection, routing, and addressing. |
| data link layer | media access control, MAC address (physical address) |
| physical layer | electrical, mechanical, procedural, and functional specifications. Think about media, physical devices,etc. |
| encapsulation | preparing information so that it can be transferred over the network. |
| data | encapsulation from Application thru Session layer |
| segments | encapsulation at the transport layer |
| packets | encapsulation at the network layer |
| frames | encapsulation at the data-link layer |
| bits | encapsulation at the physical layer. |
| TCP/IP | 4 layers: Application, Transport, Internet and Network Access |
| TCP/IP Application Layer | equivalent functions to Application, Presentation and Session layers from the OSI model |
| TCP/IP Transport Layer | equivalent functions to the Transport Layer in the OSI model |
| TCP/IP Internet Layer | Equivalent to the Network Layer in the OSI model. |
| TCP/IP Network Access Layer | Combines the functions of the Data-link and Physical Layers in the OSI model |
| Advantages of Layered Model | Reduces complexity, accelerates evolution,simplifies learning and teaching,standardizes interfaces,etc. |
