Network Topologies BUS Topology Each node is connected
Network Topologies
BUS Topology Each node is connected via a single cable, this is done with the help of interface connectors usingle cables. They are all connected in half duplex links. This is called a bus. This cable is known as the backbone of the network as well as being the BUS. A Signal from the sources will travel in both directions to all of the machines connected on the bus until i fins the recipient that requires it. If the address for the machine does not match the intended address then the machine will ignore the data. A host on a bus network is referred to as a Station or a Workstation. In a bus network all of the stations will the network traffic. All the generated traffic has an equal transmission priority. Thereceive bus network will form a single network segment and collision domain. For the nodes to be able to transmit at the same time they will use a access control technology such as Carrier Sense Multiple Access or a bus Master.
Carrier Sense Multiple Access (CSMACA/CD Carrier Sense Multiple Access Collision Avoidance. Is a network multiple access method. Where carrier sensing is used. The nodes will attempt to avoid collisions by transmitting only when the channel needed is sensed to not be in use. When the nodes transmit they will transmit the entire packet of data. This is very important for wireless networks where CSMA/CD is unreliable because of the hidden node problem. CSMA/CA is a protocol that works in the Data Link layer of the OSI model. Carrier Sense Multiple Access Collision Detect. This is another media access control method that is used mostly in local area networks. It uses Ethernet technology. It works by detecting other signals when transmitting a frame. It will transmit a jam signal if there is a collision and then will then wait for a random time before trying to resend the frame. It is used to improve Carrier Sense Multiple access Collision Avoidance. It will terminate the transmission as soon as a collision is detected.
Star Each computer is connected to a central hub with a point to connection. It can be said that every computer is indirectly connected to each other. The central hub is known as a central node, router or switch. The Switch is known as a the server The peripherals are known as the clients The network does not have look like a star to be star network. Data on a star network will pass through the central hub, switch or concentrator before continuing to the intended destination. The hub, switch of concentrator manages and controls all of the functions of the network. This configuration is usually used with a twisted pair cable and optical fibre cable. Uses CSMA/CD
Ring Set up in a circular style. This will look like a close loop. The data will travel around the ring in one direction. Each device will be a repeater making sure the signal says strong as it goes around the network. Each of the devices on the network has a receiver for the incoming signal and a transmitter to send the data around the ring. The whole network is dependent on the ability of the signal to travel around the ring. Each of the nodes on the network will be connected to exactly two other nodes on the network. This will form a route for the signals sent to be able to pass through and they will pass through each of the nodes. Data will travel through every node, and each of the nodes the data passes through will handle every packet of data sent
Token Ring Usually found in a local area network. Uses a special three-byte frame called a token. It will travel around a logical ring of workstations or servers. It is a channel access method for providing fair access for all the stations on the network. It will eliminate the collisions of contention based access methods. Data is going to be sent in sequence, it will pass from one node on the network to another. A control token will pass round the ring which is going to control access. There are other token passing methods that are similar to token ring, such as ARCNET, a TOKEN BUS.
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