networking curriculum
support CD for senior
secondary studies

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networking > technologies > hubs

Hubs

A hub is a device to connect multiple NIC's to each other. The hub replicates any incoming data from one NIC to all the other connected NIC's. So there is both the advantage and the disadvantage, every NIC 'sees' every bit of traffic from every other NIC even though the communication may only be intended between two computers out of the many. It means all computers can be networked quickly and simply which is an advantage, but as the number of pairs of communicating computers increases, the congestion on the network rises rapidly and sorting out the corrupted data and consequent resending of data over a crowded network quickly degrades performance.

However for simple networks with low data traffic, a hub is a very reliable, easy to use and economical solution. Hubs are made with 10Mhz or 100Mhz bandwidth and usually have LED indicators to indicate traffic and data collision rates. More advanced hubs are allocated MAC addresses and their activity monitored in greater detail from remote clients. The local connections to a central hub, and its connection to other hubs cause the networks to be nearly always considered to be "Star" networks, compared to coaxial cable systems that were more of the "Daisy Chain", bus topology .

Ethernet hubs also have another major limitation on a large network as the signal is simply passed though the internal wiring and is not "cleaned up" in any way and consequently when hubs are cascaded the quality of the signal degraders and quickly leads to many transmissions being corrupted and the traffic becomes congested and inefficient again. Generally speaking it is not advisable to have any more than two hubs connected in series to make up the network.

worksheets
. history
. why network
. osi model
. connecting
. protocols
. technology
. topologies (tla)
. issues
. network types
. design
. economics
. economics (cs)
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quizzes
. why network
. osi model
. connecting
. protocols
. technology
. topology
. issues
. network types
. design
. economics

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