The Role of MTP® Breakout Cables in High-Density Networking

MTP® breakout (fanout) cables split a multi-fiber MTP®/MPO connector (e.g., 8/12/24 fibers) into multiple LC/SC ports, bridging high-density backbone trunks to the lower-count interfaces on switches, servers, and storage.

Connecting Trunks to Active Equipment

  1. Backbone trunk terminates to MTP® at the MDA/EDA.
  2. (Optional) Patch panel or cassette for labeling and MACs.
  3. MTP® breakout converts to LC/SC fanout legs.
  4. Fanout legs land on SFP+/SFP28/QSFP(+) ports (breakout mode when applicable).
  • De-aggregation: One multi-fiber connector becomes multiple channelized legs (e.g., 4× LC duplex from an 8-fiber MTP®).
  • Direct or via cassette: Plug breakouts into trunks or route through cassettes.
  • Transceiver alignment: Duplex legs for SFP ports or lane splits from QSFP ports.

Why They Simplify High-Speed Data Centers

  • Density: Fewer home-run cables, cleaner racks, better airflow.
  • Plug-and-play: Factory-terminated for fast, repeatable turn-ups.
  • Scalable: Reuse trunks for 10G→40/100/200/400G with proper optics and mapping.
  • Reliable: Fewer patch points and neater paths reduce errors and maintenance time.

Common Breakout Configurations

  • MTP®-8 → 4× LC duplex
    • Port mode: 40G QSFP+ → 4×10G
    • Use: Split one 40G into four 10G server links
  • MTP®-12 → 6× LC duplex
    • Port mode: 100G QSFP28 → 4×25G or 10×10G*
    • Use: High-density ToR server attachments
  • MTP®-24 → 12× LC duplex
    • Port mode: 100/200G fanout
    • Use: Aggregation to many 10/25G ports

*Dependent on transceiver and switch support.

Design Notes

  • Polarity: Plan Type A/B/C so Tx/Rx align end-to-end.
  • Pins & gender: Match pinned vs. pinless across trunk/cassette/breakout.
  • Loss budget: Use low-loss MTP® for longer paths or cascades.
  • Fiber type: OM4/OM5 for short-reach parallel optics; OS2 for longer reach.
  • Labeling & bend radius: Label legs/ports; protect tight fanouts.
  • Optics support: Confirm switch breakout modes (e.g., 100G → 4×25G).