Cabletron Systems 100BASE-FX, Cabling Manual

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Ethernet Network Requirements
5-10 10BASE5 (Coaxial Cable)
Connectors/Taps
10BASE5 cables may be terminated with intrusive (N-Type) connectors or tapped
by coring through the cable to the transmissive core wire. Termination of the cable
segment must be accomplished with intrusive connectors. Connectors or taps on
the 10BASE5 cable must be spaced no less than 2.5 m (8.2 ft) from one another or
the cable termination. If connectors are located closer to one another than this
minimum, a loss of network performance may result.
One segment of 10BASE5 cabling can support up to 100 taps or intrusive
connectors. This number does not count the terminating connectors at each end of
the cable as taps.
Grounding
Each thick coaxial cable segment should be connected to earth ground at only one
point. The connection to a ground should not be made through an N-Type
connector unless the connection to the ground is made through the N-Type
terminator at the end of the cable. The grounding wire must be connected to the
outer metal shield of the coaxial cable and should be no longer than 10 m (3.28 ft).
If insulated, grounding wires should be green in adherence with accepted wiring
practice.
Length
10BASE5 specifications allow a thick coaxial cable segment to be no longer than
500 meters (1,646 ft). The use of longer cable segments can cause excessive error
conditions and poor network performance.