H3C Technologies H3C SR6600 - Manual (Page 76)

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• Straight-through cables connect devices of different types—for example, router to PC and router to
switch.
• Crossover cables connect devices of the same type—for example, switch to switch, router to router,
and PC to PC.
If an RJ-45 Ethernet port is enabled with MDI/MDIX autosensing, it can automatically negotiate pin roles.
NOTE:
The H3C SR6602 RJ-45 Ethernet interfaces support MDI/MDIX autosensing. By default, MDI/MDIX
autosensing is enabled on an interface.
Making an Ethernet twisted pair cable
Follow these steps to make an Ethernet twisted pair cable:
Step1 Cut the cable to a proper length with the crimping pliers.
Step2 Strip off an appropriate length of the cable sheath. The length is typically that of the RJ-45 connector.
Step3 Untwist the pairs so that they can lay flat, and arrange the colored wires based on the wiring
specifications.
Step4 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.
Step5 Crimp the RJ-45 connector with the crimping pliers until you hear a click.
Step6 Use a cable tester to verify the proper connectivity of the cable.
Optical fiber
You can use an optical fiber to connect the following interface modules: HIM-4GBP/HIM-8GBP,
HIM-CL1P/HIM-CL2P, HIM-CLS1P/HIM-CLS2P, HIM-MSP2P/HIM-MSP4P, HIM-PS1P,
HIM-AL1P/HIM-AL2P, HIM-RS2P, MIM-2GBE, MIM-1POS, and MIM-1ATM-OC3.
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 carries
only a single ray of light; a multi-mode fiber carries multiple modes of lights.
Table 31 Characteristics of single mode and multi-mode optical fibers
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
Users 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