Polling in a star network (1 Viewer)

[minicam]

How does polling work in a star network to detect collisions?

 

[Lwaxana]

What you asked:
Polling is when each terminal is polled in rotation to determine whether a message is ready to be sent. If a particular terminal has a message to be sent and the line is available, the front-end processor accepts the message and polls the next terminal.
What I teach:
The protocols used with star configurations are usually Ethernet or LocalTalk.
The Ethernet protocol is by far the most widely used. Ethernet uses an access method called CSMA/CD (Carrier Sense Multiple Access/Collision Detection). This is a system where each computer listens to the cable before sending anything through the network. If the network is clear, the computer will transmit. If some other node is already transmitting on the cable, the computer will wait and try again when the line is clear. Sometimes, two computers attempt to transmit at the same instant. When this happens a collision occurs. Each computer then backs off and waits a random amount of time before attempting to retransmit. With this access method, it is normal to have collisions. However, the delay caused by collisions and retransmitting is very small and does not normally effect the speed of transmission on the network.
The Ethernet protocol allows for linear bus, star, or tree topologies. Data can be transmitted over twisted pair, coaxial, or fiber optic cable at a speed of 10 Mbps up to 1000 Mbps.

 

[FcUk]

What you asked:
Polling is when each terminal is polled in rotation to determine whether a message is ready to be sent. If a particular terminal has a message to be sent and the line is available, the front-end processor accepts the message and polls the next terminal.
What I teach:
The protocols used with star configurations are usually Ethernet or LocalTalk.
The Ethernet protocol is by far the most widely used. Ethernet uses an access method called CSMA/CD (Carrier Sense Multiple Access/Collision Detection). This is a system where each computer listens to the cable before sending anything through the network. If the network is clear, the computer will transmit. If some other node is already transmitting on the cable, the computer will wait and try again when the line is clear. Sometimes, two computers attempt to transmit at the same instant. When this happens a collision occurs. Each computer then backs off and waits a random amount of time before attempting to retransmit. With this access method, it is normal to have collisions. However, the delay caused by collisions and retransmitting is very small and does not normally effect the speed of transmission on the network.
The Ethernet protocol allows for linear bus, star, or tree topologies. Data can be transmitted over twisted pair, coaxial, or fiber optic cable at a speed of 10 Mbps up to 1000 Mbps.

What you teach??

 

[jumb]

I've got $10 on IPT.

 

[Lwaxana]

FcUk owes jumb $10