Installation Guide

A PPENDIX B | Cables
Twisted-Pair Cable and Pin Assignments
– 61 –
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:
1. Replace any Category 5 patch cables with high-performance Category 5e or
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 International Telecommunication Union (ITU-T) has standardized various
fiber types for data networks. These are summarized in the following table.
Table 17: 1000BASE-T MDI and MDI-X Port Pinouts
ITU-T
Standard
Description Application
G.651 Multimode Fiber
50/125-micron core
Short-reach connections in the
1300-nm or 850-nm band.
G.652 Non-Dispersion-Shifted
FiberSingle-mode, 9/125-
micron core
Longer spans and extended reach.
Optimized for operation in the
1310-nm band. but can also be used
in the 1550-nm band.
G.652.C Low Water Peak
Non-Dispersion-Shifted Fiber
Single-mode, 9/125-micron
core
Longer spans and extended reach.
Optimized for wavelength-division
multiplexing (WDM) transmission
across wavelengths from 1285 to
1625 nm. The zero dispersion
wavelength is in the 1310-nm region.
G.653 Dispersion-Shifted Fiber
Single-mode, 9/125-micron
core
Longer spans and extended reach.
Optimized for operation in the region
from 1500 to 1600-nm.