91Making an Ethernet twisted pair cable1. Cut the cable to length with the crimping pliers.2. Strip off an appropriate length of the cable sheath. The length is typically that of the RJ-45connector.3. Untwist the pairs so that they can lie flat, and arrange the colored wires based on the wiringspecifications.4. Cut the top of the wires even with one another. Insert the wires into the RJ-45 end and make surethe wires extend to the front of the RJ-45 end and make good contact with the metal contacts in theRJ-45 end and in the correct order.5. Crimp the RJ-45 connector with the crimping pliers until you hear a click.6. Repeat the above steps with the other end of the cable.7. Use a cable tester to verify the connectivity of the cable.Optical fiberCAUTION:Use the same types of transceiver modules, pigtail cords, patch cords, and fiber cables. If you usesingle-mode optical fibers, the transceiver modules, pigtail cords, patch cords, and fiber cables must besingle-mode.Optical fiberOptical fibers are widely used in fiber-optic communications, which are advantageous for long-distancecommunications.Optical fibers can be classified into the following types:• Single mode fiber—It has a core size of 10 μm or smaller, and has a lower modal dispersion. Itcarries only a single ray of light. It is mostly used for communication over longer distances.• Multi-mode fiber—It has a core size of 50 μm or 62.5 μm or higher, and has a higher modaldispersion than single-mode optical fiber. It is mostly used for communication over shorterdistances.Table 54 Allowed maximum tensile force and crush loadPeriod of force Tensile load (N) Crush load (N/mm)Short period 150 500Long term 80 100Optical fiber cableAn optical fiber cable is a cable containing one or more optical fibers. The optical fiber elements aretypically individually coated with plastic layers and contained in a protective tube. Optical fiber cablesfall into single-mode and multi-mode.
