SMC Networks EZ Switch SMCGS16, Руководство пользователя

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1000BASE-T C
ABLE
R
EQUIREMENTS
11
1000BASE-T Cable Requirements
All Category 5 UTP cables that are used for 100BASE-TX connections
should also work for 1000BASE-T, providing that all four wire pairs are
connected. However, it is recommended that for all critical connections, or
any new cable installations, 4-pair Category 5e (enhanced Category 5) cable
should be used. The Category 5e specifications include test parameters
that are only recommendations for Category 5. Therefore, the first step in
preparing existing Category 5 cabling for running 1000BASE-T is a simple
test of the cable installation to be sure that it complies with the IEEE
802.3ab standards.
Cable Testing for Existing Category 5 Cable
Installed Category 5 cabling must pass tests for Attenuation, Near-End
Crosstalk (NEXT), and Far-End Crosstalk (FEXT). This cable testing
information is specified in the ANSI/TIA/EIA-TSB-67 standard.
Additionally, cables must also pass test parameters for Return Loss and
Equal-Level Far-End Crosstalk (ELFEXT). These tests are specified in the
ANSI/TIA/EIA-TSB-95 Bulletin, “The Additional Transmission
Performance Guidelines for 100 Ohm 4-Pair Category 5 Cabling.”
Note that when testing your cable installation, be sure to include all patch
cables between switches and end devices.
Adjusting Existing Category 5 Cabling
If your existing Category 5 installation does not meet one of the test
parameters for 1000BASE-T, there are basically three measures that can be
applied to try to correct the problem:
1. Replace any Category 5 patch cables with high-performance Category
5e or 6 cables.
2. Reduce the number of connectors used in the link.
3. Reconnect some of the connectors in the link.