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Network+ Exam

Fiber optic connectors

October 29, 2025

  • #network+

Fiber optic connectors

single mo

Sc subrcriber connector: known for square shape ad pysh pull deshgni that is secure and simple connection mechanisim

LC lucent conector = designed by a compact size

st straight tip connector - stick and twist to lock in used wih multi mode

mtrj e=mechanical jacj

pc - physical contacdt - used in digital and hone services profvdie the least effective reduction in back reflection.

upc- ultra physical

apc

Fiber Connectors (CompTIA Network+)

Common Connector Types

  • SC (Subscriber Connector)
    • Square shape, push–pull design.
    • Secure, simple, widely used in telecom/datacenter.
    • Common in single-mode fiber.
  • LC (Lucent Connector)
    • Smaller “little connector,” compact size.
    • Push–pull design.
    • Favored in high-density applications (datacenters).
  • ST (Straight Tip)
    • Round, stick-and-twist (bayonet) style.
    • Durable, reliable.
    • Common in multi-mode fiber.
  • MTRJ (Mechanical Transfer Registered Jack)
    • Compact, RJ-style latch.
    • Houses both transmit + receive fibers in one connector.
    • Often used in office LANs, space-saving installs.
  • MPO (Multi-Fiber Push On) (for completeness)
    • Bundles many fibers into one connector.
    • Used in high-speed datacenter backbones.

Connector Polish Types (reduces back reflection)

  • PC (Physical Contact)
    • Slight curvature on the fiber face.
    • Least effective at reducing reflection.
    • Used in early digital/phone systems.
  • UPC (Ultra Physical Contact)
    • Dome-shaped end face.
    • Better alignment, lower reflection than PC.
    • Used in broadband & general-purpose fiber.
  • APC (Angled Physical Contact)
    • End face cut at 8° angle.
    • Best reflection reduction.
    • Used in high-bandwidth, long-haul, and critical systems (ex: undersea cables).
    • Always green connectors.

✅ Exam Tips

  • SC = Square / push–pull, LC = Little / compact, ST = Stick & Twist.
  • APC = best reflection control, angled 8°.
  • If you see datacenter/high-density → LC.
  • If you see old school multi-mode → ST.

⚡ Rapid Review Q’s

  1. Which connector is compact and used in high-density racks?
  2. Which polish provides the lowest back reflection?
  3. Which connector is push–pull, square-shaped?