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Data/Telecomm Questions

Premises Wiring:

1. What is the difference between category 3, 4, and 5 cabling?
  • Category 3 is specified up to 16MHz. They are typically used for voice and data transmission rates up to and including 10 Mbps, e.g. IEEE 802.5, 4 Mbps UTP and IEEE 802.3 10 Base-T Ethernet.
  • Category 4 is specified up to 20 MHz. They are typically used for voice and data transmission rates up to and including 16 Mbps, e.g. IEEE 802.5, 4/16 Mbps UTP.
  • Category 5 is specified up to 100 MHz. They are typically used for voice and data transmission rates up to and including 100MBps, e.g.
2. What is a crossover cable?
  • A crossover cable is a segment of Category 5 cable that crosses over pins 1,2/3,6. This cable is normally used to connect 2 PCs without the use of a hub, or when cascading 2 hubs without the use of an uplink port.
3. What is the difference between a T568-A wiring scheme and a T568-B wiring scheme?
  • The only difference between the two is the actual wiring of the connector or jack.
  T568-A T568-B
Pin 8 BR BRN

4. Do you need a special tool when working with your 110 Type patch panels and jacks.
  • Yes, you need to use a 110 Type impact tool in order to properly terminate your connections.
5. What is an AUI?
  • Attachment Unit Interface (AUI) is most commonly used with reference to the 15 pin D type connector and the cables used to connect single and multiple channel equipment to an Ethernet transceiver.
6. What is Crosstalk?
  • Crosstalk is the unwanted introduction of signals from one channel or pair to another.
7. What is USOC?
  • Uniform Service Ordering Code (USOC). Terms originally used by the telephone company to specify installation of a standard modular jack other than the RJ11W or RJ11C. More recently refers to a modular standard (tip/ring sequence).
8. What is EMI?
  • Energy generated by outside sources, such as lighting systems and electric motors, which is received by copper data/voice cable and interferes with transmission.
9. Can you use telephone patch cords to connect a LAN?
  • It is not recommended for someone to use telephone cords in order to connect a LAN. Telephone cords are designed to work with low speed applications such as voice transmission.
10. Do you need a hub if using coaxial cable on a LAN?
  • No, a hub is not needed when you are using coaxial cable. You can directly connect each computer by using coaxial cable, but you must put terminators on each end of the cable.

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