Understanding the network.pdf - Back to Home

Hubs
Figure 1.9. Using repeaters to extend the cable
segment.
A hub is a multiport repeater. In Ethernet technology, there are two types of hubs:
• Active hubs—Where each of the ports is a repeater that amplifies the signal
for each connection (CMSA/CD)
• Passive hubs—Do not amplify the signal at all
In Token Ring technology, a hub is known as a Multi-Station Access Unit (MAU), and
it acts as the physical ring that all the hosts are connected to. For both Ethernet and
Token Ring, there are strict specifications for how many hubs can be employed in a
given context.
Although a repeater can be used to increase a network's size, it can, at the same,
time reduce the network's performance. This reduction in performance is due
largely to the expansion of the collision domain. Because the repeater just
retransmits signals, the load on the network increases as more stations are added to