Dual-Speed Stackable Hubs User’s Guide
Introduction
4
Dual-Speed Ethernet Hub
Technology Overview
Dual-speed Ethernet hubs have been developed to make it simpler to plan
networks containing both 10-Mbps Ethernet and 100-Mbps Fast Ethernet
technologies, especially when network hosts are being gradually migrated to
new Fast Ethernet connections.
Ethernet and Fast Ethernet workgroups, also called collision domains, are
configured in a star topology where all end-nodes (computers, servers,
bridges, etc.) branch out from a central hub. Two hubs can also be
plinked’
to each other to form a much larger collision domain consisting of two linked
stars. And collision domains can be easily interconnected through switching
hubs and bridges to form a network large enough to encompass a high-rise
building or campus environment.
A dual-speed hub is actually two repeaters in one housing. Any device that is
plugged into the hub is automatically connected (by NWay) to the fastest
repeater it can use. The 10-Mbps repeater receives Ethernet transmissions
from any port connected to it, and retransmits them to all other ports operat-
ing at 10 Mbps. Similarly, the 100-Mbps repeater retransmits Fast Ethernet
transmissions from ports operating at 100 Mbps to all other ports operating at
the same speed as shown below.
10Mbps Repeater
100Mbps Repeater
NWay Detection
RJ-45 Ports
100Mbps
Ethernet
Station
100Mbps
Ethernet
Station
10Mbps
Ethernet
Station
10Mbps
Ethernet
Station
100Mbps
Ethernet
Station