Types of Communication Links-
In computer networking,
- Communication links enable the stations to communicate with each other.
- Stations may communicate using the following types of links-
- Point to Point Link
- Broadcast Link
1. Point to Point Link-
- Point to Point link is a dedicated link that exists between the two stations.
- The entire capacity of the link is used for transmission between the two connected stations only.
- Depending upon the Type Of Channel, the data flow takes place between the stations.
2. Broadcast Link-
- Broadcast link is a common link to which multiple stations are connected.
- The capacity of the link is shared among the connected stations for transmission.
|Access Control is a mechanism that controls the access of stations to the transmission link.|
- Broadcast links require the access control.
- This is because the link is shared among several stations.
Need of Access Control-
|To prevent the occurrence of collision or if the collision occurs, to deal with it.|
Consider a situation where-
- Multiple stations place their data packets on the link and starts transmitting simultaneously.
- Such a situation gives rise to a collision among the data packets.
- Collision of data packets causes the data to get corrupt.
Consider the following scenario-
- Two stations A and D starts transmitting their data packets simultaneously.
- This situation gives rise to a collision between the data packets transmitted by them.
- Thus, to prevent the collision or to deal with it, access control is needed.
Access Control Methods-
|Access control methods are the methods used for providing access control.|
- They prevent the collision or deal with it and ensures smooth flow of traffic on the network.
- They are implemented at the data link layer of the OSI reference model.
Various access control methods used are-
We will discuss all these methods one by one in detail.
To gain better understanding about Access Control,
Next Article- Time Division Multiplexing (TDM)
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