hello and this is sunny welcome back today my topic is csma/cd the acronym csma/cd stands for carrier sense multiple access with a clearing detection it is a media access control method used in the early internet technology the term may seem intimidating but if we break it apart and they demonstrate how it works by the end of the video I believe you will have a pretty clear idea [Music] let me explain CSMA first carrier refers to transmission media such as an electronic bus in Ethernet network or band of electromagnetic spectrum or channel II Wi-Fi network the
media carries data that's why we call it carrier carrier sense just as a human beings health fiber senses such as a sight sound smell taste and touch a node on a network also has has a sense it can listen can hear it can detect was going on over the transmission media keep in mind when we see a node has a sense we really means a network interface card or NIC has assessed multiple access it means every node in the network has equal right to access to and use the shared media but they must take turns
when we put these four words together carrier sense multiple access means before a node transmits a data it checks or listens to the media when the media is not a busy the node sense is data if it detects the media is used by the other nodes it will back off and a wait for a random amount of a time and try again CSMA is just like a traffic protocol at a four-way stop in Kansas the protocol is no cop no stop just kidding at a four-way stop or always stop every driver must come to full
stop and then check the state of junction before she or he can proceed every driver has an equal right to use the junction but they must have follow first come first serve the rules now let me talk about a CD say these stands for clearing detection which means a note can hear clicking if that happens for example both the a and sa wanted to transmit their data and if they check the media and find it is not a busy therefore they send the message at the same time well clearing occurs when these two notes hear
the collision they will back off and use some kanva randomization to decide which would go first in order to avoid clicking again csma/cd is an older technology and used in early internet device such as we talk about it because CompTIA certification tests still cover it and understanding it would be also helpful to understand Wi-Fi access method csma/ca which i will talk about in next video thank you very much and see you next time [Music]
