Computer Network presentation of Computer Network Group Name

Computer Network

presentation of Computer Network �Group Name: � �Program: �Instructor: Ij. Az Ib. Ra. Hi. M. Ghulam Mustufa Shad Ali Safi BSSE(B) Mr. Tahir Juniad

CSMA/CD �Carrier Sense Multiple Access with Collision Detection (CSMA/CD) is the LAN access method used in Ethernet. When a device wants to gain access to the network, it checks to see if the network is free.

CSMA/CD �If the network is not free, the device waits a random amount of time before retrying. If the network is free and two devices access the line at exactly the same time, their signals collide.

CSMA/CD �When the collision is detected, they both back off and wait a random amount of time before retrying. �CSMA/CD is a Media Access Control (MAC) protocol.

CSMA/CD �CSMA/CD is a Media Access Control (MAC) protocol. It defines how network devices respond when two devices attempt to use a data channel simultaneously and encounter a data collision

CSMA/CD �The CSMA/CD rules define how long the device should wait if a collision occurs. The medium is often used by multiple data nodes, so each data node receives transmissions from each of the other nodes on the medium.

CSMA/CD �CSMA ACCESS MODES � 1 -persistent �P-persistent �O-persistent

CSMA/CD � 1 -persistent is used in CSMA/CD systems, like Ethernet. This mode waits for the medium to be idle, then transmits data.

CSMA/CD � P-Persistent �P-persistent is used in CSMA/CA systems, like Wi-Fi. This mode waits for the medium to be idle, then transmits data with a probability p. If the data node does not transmit the data (a probability of 1 - p), the sender waits for the medium to be idle again and transmit the data with the same probability p

CSMA/CD �O-persistent �Each node is assigned a transmission order by a supervisory node. When the transmission medium goes idle, nodes wait for their time slot in accordance with their assigned transmission order. The node assigned to transmit first transmits immediately. The node assigned to transmit second waits one time slot (but by that time the first node has already started transmitting). Nodes monitor the medium for transmissions from other nodes and update their assigned order with each detected transmission (i. e. they move one position closer to the front of the queue) O-persistent CSMA is used by Cobra. Net , Lon. Works

CSMA/CD �Cobra. Net is a combination of software, hardware, and network protocols designed to deliver uncompressed, multi-channel, low-latency digital audio over a standard Ethernet network.

CSMA/CD �Lon. Works (local operating network) is a networking platform specifically created to address the needs of control applications. The platform is built on a protocol created by Echelon Corporation for networking devices over media such as twisted pair, power lines, fiber optics

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