From Mycomputer Notes

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-	[[IMAGE:8_bridge.JPG|500px|center|1 Bridge two collision domains]]	+	[[IMAGE:8_bridge.JPG|525px|center|1 Bridge two collision domains]]

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Revision as of 00:20, 14 March 2006

Ethernet is a shared Media meanning that only one node can transmit data at any given time. The more nodes are added the more the demand of the bandwith will increase. The more nodes are added to the the media(wire) the higher the probability of collisions to occur and retramissions will increase.

A solution when adding more nodes is to break large segments into parts and separate them into different collision domains. This can be accomplished through Bridges and swithces. With a bridge this is possible because the device keeps a table of MAC addresses and the associated ports. Normally a bridge has only 2 ports and divides a collision domain into to parts.

A Bridge will:

• Divide a collision domain NOT effect on logical or broadcast domain
• Creates morcollision domains NOT add broadcast domains.

Poperties of half duplex - Only one host can transmit at a time becayse the NIC needs to listeen for collisions.

The NIC provides several circuit.ost important are:

• received (RX)
• transmit (TX)
• Collision Detection
• Banwith usage = 50% to 60%

CSMA/CD

The first device to detect the collision will generate a jam signal (colliding devices continue to transmit so that all devices will hear the collision)

• Network Congestions:
• Relieving congestion requires
• Increasing the amount of bandwidth and/or
• Using available bandwidth more efficiently

Network Latency

Network Latency ;

Represenet the itime it takes a fram to travel from is source device to its final destination onthe network. Latency can also de described as the delauy between the time a device request access to a network and the time it is granted [ermission to transmit.

Trasnmission time;

It is the time necessary to move a packet from the data link layer to the physical layer.

• Bridge stores the entire frame before it fowards it. (store-and-forward)

Symmetric switching

provides switched connections between ports with the same bandwidth (10/10 Mbps or 100/100 Mbps).(can cause bottlenecks as users try to access servers on other segments)