# Tokyo, Japan → Johannesburg, South Africa RTT

🇯🇵 **Tokyo, Japan (TYO)** → 🇿🇦 **Johannesburg, South Africa (JNB)**

Measurement round: `2026-08-16T04:07:28Z`.

Tokyo to Johannesburg averaged 359.2 ms, compared with a 132.57 ms city-centre fiber reference. The difference cannot be assigned to a particular cable or carrier from RTT alone.

Standard deviation was 15.79 ms, or 4.4% of the average. This describes variation within the sample without identifying its cause.

## Latency Summary

| Metric               | Value                                                      |
| -------------------- | ---------------------------------------------------------- |
| RTT                  | **359.2 ms**                                               |
| Jitter               | **13 ms**                                                  |
| Packet Loss          | **0%**                                                     |
| Standard Fiber Floor | **132.57 ms**                                              |
| Fiber Efficiency     | **36.9%**                                                  |
| Latency Tier         | High                                                       |
| Source Region        | [Asia Pacific](/docs/network/latency/regions/asia-pacific) |
| Destination Region   | [Africa](/docs/network/latency/regions/africa)             |

## Ping Measurement Series

50 ICMP echo probes were recorded in this round. Individual replies and their distribution are shown below.

## Download This Route's Data

Download the probe round as CSV, JSON or YAML under CC BY 4.0. [Citation details](#about-this-measurement) include the route and round timestamp.

## Theoretical Fiber Latency

The propagation model uses public city-centre coordinates from GeoNames: [Tokyo](https://www.geonames.org/1850147) (35.68950, 139.69171) and [Johannesburg](https://www.geonames.org/993800) (-26.20227, 28.04363). These are not facility coordinates or a surveyed cable path.

| Physical Reference                            | Value           |
| --------------------------------------------- | --------------- |
| WGS-84 geodesic distance                      | **13,537.7 km** |
| Vacuum RTT floor                              | **90.31 ms**    |
| Standard fiber RTT floor ($n_g=1.4679$)       | **132.57 ms**   |
| Low-latency fiber material floor              | **132.04 ms**   |
| Engineering floor (5% path allowance)         | **139.22 ms**   |
| Research 1.33× mapped-fiber reference         | **176.32 ms**   |
| Estimated unamplified path loss               | **2842.9 dB**   |
| Transparent optical spans / inline amplifiers | **178 / 177**   |
| Published RTT inflation over fiber floor      | **2.71×**       |

The span count assumes 80 km optical spans. Attenuation is a power-loss term, not a propagation delay. See the [model assumptions and equations](/docs/network/latency/theoretical-fiber-latency).

## Stability & Trend

Statistics from the same 50 replies. They describe this probe round, not continuous historical monitoring.

| Round Statistic    | Value         |
| ------------------ | ------------- |
| Minimum RTT        | **339.59 ms** |
| Average RTT        | **359.2 ms**  |
| Maximum RTT        | **411.36 ms** |
| Standard deviation | **15.79 ms**  |
| Stdev / average    | **4.4%**      |

## Route Context

* Departure PoP: [Tokyo (TYO)](/docs/network/latency/tyo-tokyo)
* Destination PoP: [Johannesburg (JNB)](/docs/network/latency/jnb-johannesburg)
* Region overview: [Asia Pacific](/docs/network/latency/regions/asia-pacific) → [Africa](/docs/network/latency/regions/africa)
* Full global matrix: [Backbone Latency Matrix](/docs/network/latency)
* Physical methodology: [Theoretical Fiber Latency](/docs/network/latency/theoretical-fiber-latency)

## Related City-Pair Routes

**Reverse direction**

* [Johannesburg to Tokyo latency and RTT](/docs/network/latency/pairs/jnb-tyo-rtt): 360.5 ms

**Fastest routes departing Tokyo (TYO)**

* [Tokyo to Taipei latency and RTT](/docs/network/latency/pairs/tyo-tpe-rtt): 32.3 ms
* [Tokyo to Hong Kong latency and RTT](/docs/network/latency/pairs/tyo-hkg-rtt): 44.8 ms
* [Tokyo to Singapore latency and RTT](/docs/network/latency/pairs/tyo-sin-rtt): 69.4 ms
* [Tokyo to Seattle latency and RTT](/docs/network/latency/pairs/tyo-sea-rtt): 84.8 ms
* [Tokyo to Los Angeles latency and RTT](/docs/network/latency/pairs/tyo-lax-rtt): 101.2 ms

**Fastest routes arriving at Johannesburg (JNB)**

* [Amsterdam to Johannesburg latency and RTT](/docs/network/latency/pairs/ams-jnb-rtt): 171.9 ms
* [Berlin to Johannesburg latency and RTT](/docs/network/latency/pairs/ber-jnb-rtt): 172.1 ms
* [London to Johannesburg latency and RTT](/docs/network/latency/pairs/lon-jnb-rtt): 179.6 ms
* [Paris to Johannesburg latency and RTT](/docs/network/latency/pairs/par-jnb-rtt): 180.9 ms
* [Frankfurt to Johannesburg latency and RTT](/docs/network/latency/pairs/fra-jnb-rtt): 188.4 ms

**Same corridor (Asia Pacific → Africa)**

* [Singapore to Johannesburg latency and RTT](/docs/network/latency/pairs/sin-jnb-rtt): 312.6 ms
* [Hong Kong to Johannesburg latency and RTT](/docs/network/latency/pairs/hkg-jnb-rtt): 316.7 ms
* [Taipei to Johannesburg latency and RTT](/docs/network/latency/pairs/tpe-jnb-rtt): 331 ms

## About This Measurement

These ICMP measurements cover the two backbone endpoints. Access networks, routing policy and load can change an end user's result. A probe round is not an SLA.

The underlying replies are available under **CC BY 4.0** in the [Hats Network latency dataset](/opendata/latency/). Per-pair files are available at `/opendata/latency/latest/pairs/tyo-jnb.pings.{csv,json,yaml}`. Cite the route, round timestamp and dataset version. Example: "Hats Network latency dataset, Tokyo → Johannesburg round 2026-08-16T04:07:28Z, CC BY 4.0".

***

*Round published August 16, 2026. See the [full interactive latency matrix](/docs/network/latency) or browse more [city-pair routes](/docs/network/latency/pairs).*

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## License and attribution

- **Canonical source:** [View the human-readable HTML page](https://hatsnet.io/docs/network/latency/pairs/tyo-jnb-rtt).
- **Original documentation:** © Hats Network Inc., licensed under [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/).
- **Public latency data:** © Hats Network Inc., licensed under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/).
- **Full terms:** [Content and Data License](https://hatsnet.io/docs/legal/content-and-data-license) — includes attribution requirements, third-party material, trademarks, source code and other exclusions.