Route Latency & Path-Inflation Checker

Best-case physics vs. real-world latency. Uses ~4.9 μs/km in single-mode fiber (n≈1.468), plus overheads you control.

Route distance

If you only have straight-line distance, add path inflation below.

Path inflation

0%15%50%

Real routes exceed straight-line due to rights-of-way, bends, and entrance diversity.

Effective refractive index (n)

Typical SMF: n ≈ 1.467–1.468 at 1310–1550 nm. Lower n → faster propagation.

Hops (L1/L2 devices)

Per-hop processing (ms)

Serialization / queuing allowance (ms)

Estimate serialization delay (optional)

Frame size (bytes)

Line rate (Gbps)

Serialization (one-way): —

Latency target (one-way ms)

“Near” band (± ms)

Set the tolerance around your SLA where results show NEAR (edge of compliance).

Quick presets

One-way (best-case, propagation only)

—

RTT (best-case)

—

One-way (real-world est.)

—

RTT (real-world est.)

—

SLA: —

Note: “Best-case” excludes device/serialization delays. “Real-world” includes your overhead settings.

Route details

Effective distance

—

Effective distance (mi)

—

Vacuum lower bound

3.3356 μs/km

Fiber constant

—

Propagation (one-way)

—

Overheads (one-way)

—

Shareable summary

Assumptions: one-way propagation time in fiber ≈ 4.9 μs/km (n≈1.468). Vacuum lower bound is 3.3356 μs/km. Real-world adds path inflation and device/serialization/queuing allowances. Estimates are for planning.