H3C Technologies H3C SecPath F1000-E - Manual (Page 88)

80
Pin
10Base-T/100Base-TX 1000Base-T
Signal Function Signal Function
5 Reserved N/A BIDD- Bi-directional data cable D-
6 Tx- Send data BIDA- Bi-directional data cable A-
7 Reserved N/A BIDC+ Bi-directional data cable C+
8 Reserved N/A BIDC- Bi-directional data cable C-
To ensure normal communication, the pins for sending data on one port should correspond to the pins
for receiving data on the peer port. When both of the ports on the two devices are MDI or MDIX, a
crossover Ethernet cable is needed. A cross-over cable connects devices of the same type. When one
port is MDI and the other is MDIX, a straight-through Ethernet cable is needed. A straight-through cable
connects devices of different types.
An RJ-45 Ethernet interface with MDI/MDIX autosensing enabled can automatically negotiate pin roles.
The UTM device RJ-45 Ethernet interfaces support MDI/MDIX. By default, MDI/MDIX is enabled on a
port.
Making an Ethernet twisted pair cable
To make an Ethernet twisted pair cable:
1. 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-45
connector.
3. Untwist the pairs so that they can lie 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. Repeat the above steps with the other end of the cable.
7. Use a cable tester to verify the proper connectivity of the cable.
Optical fiber
Optical fibers are widely used in fiber-optic communications, which are advantageous for long-distance
communications.
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. It
carries 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 modal
dispersion than single-mode optical fiber. It is mostly used for communication over shorter
distances.