1. JaringanKomputerDasar Data Link Layer (1) Aurelio Rahmadian

2. Objektif • Data Link Layer • Teknik Media Access Control

3. Data Link Layer

4. Data Link Layer • The Data Link layer provides a means for exchanging data over a common local media. • The Data Link layer performs two basic services: • Allows the upper layers to access the media using techniques such as framing • Controls how data is placed onto the media and is received from the media using techniques such as media access control and error detection • As with each of the OSI layers, there are terms specific to this layer: • Frame - The Data Link layer PDU • Node - The Layer 2 notation for network devices connected to a common medium • Media/medium (physical) - The physical means for the transfer of information between two nodes • Network (physical) - Two or more nodes connected to a common medium

5. Data Link Layer

6. Data Link Layer

7. Data Link Layer • Data Link layer protocols require control information to enable the protocols to function. Control information may tell: • Which nodes are in communication with each other • When communication between individual nodes begins and when it ends • Which errors occurred while the nodes communicated • Which nodes will communicate next

8. Data Link Layer

9. Data Link Layer

10. Data Link Layer

11. Data Link Layer

12. Teknik Media Access Control • Media access control is the equivalent of traffic rules that regulate the entrance of motor vehicles onto a roadway. The absence of any media access control would be the equivalent of vehicles ignoring all other traffic and entering the road without regard to the other vehicles. • The method of media access control used depends on: • Media sharing - If and how the nodes share the media • Topology - How the connection between the nodes appears to the Data Link layer

13. Teknik Media Access Control

14. Teknik Media Access Control

15. Teknik Media Access Control

16. Teknik Media Access Control • Media access control protocols for non-shared media require little or no control before placing frames onto the media. These protocols have simpler rules and procedures for media access control. Such is the case for point-to-point topologies.

17. Teknik Media Access Control