H3C Technologies H3C SecPath F5000-S Firewall - Manual (Page 79)

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2. Strip off an appropriate length of the cable sheath. The length is typically that of the RJ-45
connector.
3. Untwist the pairs so that they can lay flat, and arrange the colored wires based on the wiring
specifications.
4. Cut the top of the wires even with one another. Insert the wires into the RJ-45 end and make sure
the wires extend to the front of the RJ-45 end and make good contact with the metal contacts in the
RJ-45 end and in the correct order.
5. Crimp the RJ-45 connector with the crimping pliers until you hear a click.
6. Use a cable tester to verify the connectivity of the cable.
Optical fiber
Optical fibers feature low loss and long transmission distance.
Optical fibers can be classified into single mode fibers and multi-mode fibers. A single mode fiber (with
yellow jacket) carries only a single ray of light; a multi-mode fiber (with orange jacket) carries multiple
modes of lights.
Table 38 Characteristics of single mode and multi-mode optical fibers
Item Single mode fiber Multi-mode fiber
Core Small core (10 micrometers or less)
Larger core than single mode fiber (50
micrometers, 62.5 micrometers or greater)
Dispersion Less dispersion
Allows greater dispersion and therefore,
signal loss exists.
Light source and
transmission distance
Uses lasers as the light source often
within campus backbones for distance
of several thousand meters
Uses LEDs as the light source often within
LANs or distances of a couple hundred
meters within a campus network
Table 39 Allowed maximum tensile force and crush load
Period of force Tensile load (N) Crush load (N/mm)
Short period 150 500
Long term 80 100
Fiber connectors are indispensable passive components in an optical fiber communication system. They
allow the removable connection between optical channels, which makes the optical system debugging
and maintenance more convenient. There are multiple types of fiber connectors. Figure 50 shows an LC
connector.
Figure 50 Appearance of an LC connector
Follow these guidelines when you connect an optical fiber: