Examkin

Question

Difficulty: HardNetwork Cable Types and Connectors

A technician is terminating a custom UTP Ethernet patch cable intended to connect a workstation directly to a patch panel wall jack wired using the ANSI/TIA-568-B standard. While crimping the workstation RJ45 connector, the technician accidentally transposes the green pair and orange pair, wiring that connector to the ANSI/TIA-568-A standard while leaving the patch panel end terminated to ANSI/TIA-568-B. Which of the following best describes the classification of this cable and its operational behavior when connected between the workstation and a modern auto-MDIX network switch port?

  1. The technician constructed a crossover cable; the auto-MDIX feature on the switch port will automatically detect and reconfigure the transmit and receive signals to establish normal Gigabit network connectivity.Answer
  2. B
    The technician constructed a crossover cable; the connection will fail to establish a link because modern Gigabit Ethernet switches strictly require T568B straight-through cabling on all switch ports.
  3. C
    The technician constructed a rollover cable; physical layer communication will fail completely because pin 1 connects to pin 8 on opposite ends.
  4. D
    The technician constructed a straight-through cable with split pairs; the workstation will negotiate a 10 Mbps half-duplex link due to severe near-end crosstalk (NEXT).

Answer

The technician constructed a crossover cable; the auto-MDIX feature on the switch port will automatically detect and reconfigure the transmit and receive signals to establish normal Gigabit network connectivity.
The ANSI/TIA-568-A and ANSI/TIA-568-B standards differ primarily by transposing the green (pins 1 & 2) and orange (pins 3 & 6) pairs. Wiring T568A on one end and T568B on the opposite end creates a standard Ethernet crossover cable. Modern network hardware includes Auto-MDIX (Automatic Medium Dependent Interface Crossover), which automatically detects pin configurations and adjusts internal signal routing so full network communication is maintained.

Step-by-Step Solution

1
Analyze the cable pinout configuration on both ends.
One RJ45 connector is terminated to T568A and the other is terminated to T568B.
T568A swaps the green pair (pins 1 & 2) and orange pair (pins 3 & 6) relative to T568B.
2
Identify the cable classification created by mismatched T568A and T568B terminations.
A cable with T568A on one end and T568B on the other is classified as an Ethernet crossover cable.
Crossover cables cross the transmit pair (TX) to receive pair (RX) between two endpoints.
3
Determine how modern network interface hardware handles crossover cabling.
The auto-MDIX protocol automatically detects the pinout and negotiates full connectivity.
Auto-MDIX eliminates the requirement for dedicated crossover cables between legacy host-to-host or switch-to-switch interfaces.

Key Concept

T568A vs T568B Pinout Standards and Auto-MDIX Behavior
Rate this question

Topics

Network Cable Types and Connectors

More questions from this topic