IBM 8237, Installation And User Manual

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8237 Hub Installation and Planning Guide
Maximum Segment Lengths
An Ethernet segment is the total length of cable between either two repeaters or
between a repeater and an attached device. The different types of Ethernet
supported by the 8237 place different limitations on segment lengths.
Table 1-1. Maximum Segment Lengths for the Supported Ethernet Types
Ethernet Type Maximum Segment Length
10BASE2 185 m (607 ft)
10BASE5 500 m (1640 ft)
10BASE-T
or
100BASE-TX
100 m (328 ft)
10BASE-FL 2000 m (6561 ft)
Full- and half-duplex
FOIRL 1000 m (3280 ft)
100BASE-FX 412 m (1352 ft)
Half-duplex
2000 m (6561 ft)
Full-duplex
Four-Repeater Limit
The IEEE 802.3 Ethernet standard specifies that a maximum of four repeaters can
be placed in the path between any two devices in one collision domain.
Count a stack as one repeater hop as long as the total Stack Link cable length is
less than 45.7 m (150 ft). If the total Stack Link cable length is between 45.7 m (150
ft) and 75 m (246 ft), count a stack as one and one-half repeater hops.
Note: There may be more than four repeaters within a collision domain, as long as
there are no more than four repeaters in the path between any two devices in the
collision domain.
Cables and Connectors
Cable and connector requirements differ depending on the port to which each cable
connects.
UTP and STP cable pinouts can be found in Appendix A, "Cable Pinout Diagrams."
Cabling Requirements for 10BASE-T Ports
This section describes the cables required to connect the 8237’s 10BASE-T ports to
network devices such as workstations and servers.
Problems with LANs are frequently due to incorrect cable selection or poor cabling
practices. You should select components carefully and inspect installations for good
installation practices so that your 10BASE-T network will operate as intended.
Your 10BASE-T network will operate correctly on category 3, 4, or 5, 100-ohm UTP
or ScTP cable and connecting hardware, as specified in the ANSI/TIA/EIA 568-A or
CSA T529 standards. Your 10BASE-T network will also operate on 150-ohm STP-A