Jaringan Komputer Dasar Data Link Layer (1) Aurelio Rahmadian

Objektif Data Link Layer Teknik Media Access Control

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: o Allows the upper layers to access the media using techniques such as framing o 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: o Frame - The Data Link layer PDU o Node - The Layer 2 notation for network devices connected to a common medium o Media/medium (physical) - The physical means for the transfer of information between two nodes o Network (physical) - Two or more nodes connected to a common medium

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

Data Link Layer

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

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.

Teknik Media Access Control