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CHAPTER 5: Making Connections
5.2 Connectivity Rules
Ethernet (10-Mbps) networks have the following connectivity rules:
• The maximum length of a twisted-pair cable segment is 100 meters (328 ft.).
Cabling should be Category 3 or better.
• Between any two end-stations in a collision domain, there may be up to five
cable segments and four intermediate repeaters (hubs, hub stacks, or other
repeaters). Use 10-Mbps Ethernet repeaters to connect in your 10-Mbps
network segments to avoid the limitations of Fast Ethernet. Because if you
haven’t used pure 10-Mbps Ethernet repeaters in these network segments,
then these segments must operate under the rules of Fast Ethernet Standards
in those Dual-Speed Ethernet products that you use now.
• If there is a path between any two end-stations containing five segments and
four repeaters, then at least two of the cable segments must be point-to-point
link segments (for example, 10BASE-T or 10BASE-FL), while the remaining
segments may be populated (mixing) segments (for example, 10BASE2 or
10BASE5).
Fast Ethernet (100-Mbps) networks have the following connectivity rules:
• The maximum length of a twisted-pair segment (that is, the distance between a
port in the hub to a single-address network device such as a PC, server, or
Ethernet switch) is 100 meters (328 ft.). Cabling and other wiring should be
certified as Category 5 UTP or shielded twisted-pair (STP).
• The maximum diameter in a collision domain is about 205 meters (673 ft.)
using two Class II hubs (or hub stacks).
• Between any two end-stations in a collision domain, there may be up to three
cable segments and two Class II hubs or hub stacks.
5.3 Hub to End-Station Connection
After installing the hub properly, it can support up to 24 ports or 16 ports of end-
station connections. Fast Ethernet connections require either a Category 5 or
better UTP or STP cable. These cables can be up to 100 meters (328 ft.) long.
Each Ethernet connection requires a Category 3 or better UTP cable. We
recommend using Category 5 or better cabling for all connections in order to
make it easier to transition all stations to 100 Mbps.
