10Base-T; Utp Wiring Specifications - Allied Telesis CentreCOM AT-3675 Bridge User Manual

Appendix A
Data Cabling Techniques

10BASE-T

UTP Wiring
Specifications
Depending on the medium you choose, there are certain wiring practices you
should follow to ensure the reliability of communication throughout the
network. The following sections detail cabling techniques and port
specifications for IEEE 802.3 media. For comprehensive treatment of these
topics, refer to the original IEEE specification.
The maximum length for 10BASE-T UTP segments is 100 meters (328 ft.).
10BASE-T requires UTP wiring capable of supporting 10 megabit data rates.
A serious problem exists concerning identification of modular cable. There
are various grades of voice-quality and data-quality cables available. These
can appear to be similar externally, although their high-speed data
transmission characteristics are radically different.
The identification problem is exaggerated by the fact that some suppliers
have sold data-quality cables manufactured with voice-quality cabling.
If any voice-quality cabling is used in a 10BASE-T network system, data
movement is slow, collision-prone or non-existent. To confuse the issue, the
Link indicator on the interface will usually indicate a valid link in such a case.
For the foregoing reasons, it is absolutely vital that all cabling used with the
10BASE-T connections is of Level 3, 4 or 5. The wire should be 22 to 26
American Wire Gauge (AWG), 100
Following these guidelines will help maintain 10 megabit data integrity
throughout the wiring system.
As a rule of thumb, if a cable type is flat, it is typically untwisted, and will
cause problems. If a cable is more or less round in section, it will typically
work. "Silver Satin" flat cable is out of specification and should not be used.
The six common modular cable specifications and their applicability to
10BASE-T network use are shown in Table 7.
impedance with 3 to 8 twists per foot.
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