Milan mil-sm24004tg Installationsanweisungen
B-4
Cables
B
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.”
(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.
between switches and end devices.
Adjusting Existing Category 5 Cabling to Run 1000BASE-T
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 and
correct the problem:
1000BASE-T, there are basically three measures that can be applied to try and
correct the problem:
1.
Replace any Category 5 patch cables with high-performance Category 5e or
Category 6 cables.
Category 6 cables.
2.
Reduce the number of connectors used in the link.
3.
Reconnect some of the connectors in the link.
Fiber Standards
The current TIA (Telecommunications Industry Association) 568-A specification on
optical fiber cabling consists of one recognized cable type for horizontal subsystems
and two cable types for backbone subsystems.
optical fiber cabling consists of one recognized cable type for horizontal subsystems
and two cable types for backbone subsystems.
Horizontal 62.5/125 micron multimode (two fibers per outlet).
Backbone 62.5/125 micron multimode or singlemode.
Backbone 62.5/125 micron multimode or singlemode.
TIA 568-B will allow the use of 50/125 micron multimode optical fiber in both the
horizontal and backbone in addition to the types listed above. All optical fiber
components and installation practices must meet applicable building and safety
codes.
horizontal and backbone in addition to the types listed above. All optical fiber
components and installation practices must meet applicable building and safety
codes.