Computer Concepts
Sheet1
| OSI_Layer | LayerNum | Function | DataType | NetworkComponents |
| Application layer | 7 | Supports the communication between applications over the network | User data | Gateway |
| Presentation layer | 6 | Presents data to the receiver in a form it recognises | Encoded user data | Gateway, Redirector |
| Session layer | 5 | Establishes a connection and terminates it when no longer required | Sessions | Gateway |
| Transport layer | 4 | Acknowledges the flow of data including re-transmission where required | Datagram's/Segments | Gateway, Advanced cable tester brouter |
| Network layer | 3 | Adds the appropriate network addresses to packets | Dtagram's/Packets | Brouter, router, fram relay device ATM switch, advanced cable tester |
| Data link layer | 2 | Adds the MAC addresses to packets | Frames | Brider, switch, ISDN router, intelligent hub, NIC, advanced cable tester |
| Physical layer | 1 | Transmits the data on the medium | Bits | Repeater, multiplexer, hubs TDR oscilioscope amplify |
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OSI_Layer
LayerNum
Function
Application layer
7
Supports the communication between applications over the network
Presentation layer
6
Presents data to the receiver in a form it recognises
Session layer
5
Establishes a connection and terminates it when no longer required
Transport layer
4
Acknowledges the flow of data including re-transmission where required
Network layer
3
Adds the appropriate network addresses to packets
Data link layer
2
Adds the MAC addresses to packets
Physical layer
1
Transmits the data on the medium