My Home Fibre Network Disintegrated

Original Article ↗ Hacker News Discussion ↗

Possible Causes of Degradation

  • Many commenters find the speed and severity of plastic decay unusually high for indoor storage.
  • Strong suspicion falls on material choice: the jacket is TPU, which is known to hydrolyze, especially in hot, humid environments.
  • Singapore-like humidity is cited as a stressor, but doesn’t explain why only one end degraded.
  • Several speculate paint solvents or thinners outgassing in the small room attacked the jacket; that would explain why the other ends in different spaces are fine.
  • Ozone and radon are mentioned; consensus is that naturally occurring radon/alpha radiation is far too weak to damage plastics at this rate.

Extent of Damage vs. Network Effect

  • Multiple people note the metal spiral armor and Kevlar strength members look intact; the crumbling seems limited to the outer jacket.
  • Several argue fiber links are usually “works or doesn’t”; a 30–40% speed loss is more likely due to TCP, peering, or equipment limits than partial optical damage.
  • Recommended checks: transceiver signal strength/DDM, FEC error counters, Ethernet error stats, and possibly an OTDR trace.

Fiber Construction, Robustness & Installation

  • Armored cable is compared to bike brake cables: core with fibers, armor, Kevlar, then jacket. The actual fiber is surprisingly tough if bend radius is respected.
  • Some criticize the large unanchored loops; building/underground cables should be cut to length, fixed, and landed on a patch panel, with short patch leads to equipment.
  • Service loops are fine if properly supported and within bend specs (especially for G.657.A2 bend-insensitive fiber).

Conduit & Replacement Best Practices

  • Many stress conduits as the main “future-proofing”: rigid PVC or duct, not direct embed in concrete.
  • Common advice: always pull at least one string with the first cable, keep spare strings, use cable lube, or vacuum+plastic-bag tricks to add pull lines later.
  • Shared conduits and many sharp bends make replacements harder; pull boxes and straighter runs are encouraged.

Material & Environment Lessons

  • TPU’s marketed “water resistance” conflicts with its known hydrolysis behavior; PVC/PE jackets are often more durable (subject to local fire codes and alkalinity in concrete).
  • Analogous failures are cited in shoe soles and automotive bio-based insulation where plasticizers migrate out or hydrolysis/heat accelerates decay.

“Military Grade” Debate

  • Long subthread argues “military grade” on consumer products is usually unregulated marketing, often equated with lowest-bidder quality.
  • Distinction is drawn between vague labels (“military grade”, “MIL-SPEC”) and explicit compliance with named MIL‑STD/MIL‑PRF documents, which can genuinely indicate robustness but add cost and paperwork.
  • Consensus: for home use, genuine telecom/industry-spec cable is preferable to buzzword-branded “military grade”.

Fiber vs. Copper in Homes

  • Reasons cited for using fiber: longer reach, higher practical speeds, much lower power and heat than 10GBASE‑T, and galvanic isolation (e.g., between buildings).
  • Several recommend single-mode fiber in walls for long-term future proofing; copper at 10G is probably near its practical limit for typical home distances.

Overall Takeaways

  • Design every permanent run so it can be replaced.
  • Choose jacket materials appropriate for humidity, chemicals, and concrete.
  • Don’t assume visual jacket damage implies optical failure; measure first.