# Sydney, Australia → Johannesburg, South Africa RTT

🇦🇺 **Sydney, Australia (SYD)** → 🇿🇦 **Johannesburg, South Africa (JNB)**

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

Sydney to Johannesburg averaged 412.5 ms, compared with a 108.32 ms city-centre fiber reference. The difference cannot be assigned to a particular cable or carrier from RTT alone.

Standard deviation was 12.82 ms, or 3.1% of the average. This describes variation within the sample without identifying its cause.

## Latency Summary

| Metric               | Value                                                      |
| -------------------- | ---------------------------------------------------------- |
| RTT                  | **412.5 ms**                                               |
| Jitter               | **9.3 ms**                                                 |
| Packet Loss          | **0%**                                                     |
| Standard Fiber Floor | **108.32 ms**                                              |
| Fiber Efficiency     | **26.3%**                                                  |
| 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: [Sydney](https://www.geonames.org/2147714) (-33.86785, 151.20732) 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                      | **11,060.7 km** |
| Vacuum RTT floor                              | **73.79 ms**    |
| Standard fiber RTT floor ($n_g=1.4679$)       | **108.32 ms**   |
| Low-latency fiber material floor              | **107.88 ms**   |
| Engineering floor (5% path allowance)         | **113.75 ms**   |
| Research 1.33× mapped-fiber reference         | **144.06 ms**   |
| Estimated unamplified path loss               | **2322.8 dB**   |
| Transparent optical spans / inline amplifiers | **146 / 145**   |
| Published RTT inflation over fiber floor      | **3.81×**       |

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        | **399.32 ms** |
| Average RTT        | **412.5 ms**  |
| Maximum RTT        | **451.86 ms** |
| Standard deviation | **12.82 ms**  |
| Stdev / average    | **3.1%**      |

## Route Context

* Departure PoP: [Sydney (SYD)](/docs/network/latency/syd-sydney)
* 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 Sydney latency and RTT](/docs/network/latency/pairs/jnb-syd-rtt): 412.6 ms

**Fastest routes departing Sydney (SYD)**

* [Sydney to Melbourne latency and RTT](/docs/network/latency/pairs/syd-mel-rtt): 9.8 ms
* [Sydney to Singapore latency and RTT](/docs/network/latency/pairs/syd-sin-rtt): 94.5 ms
* [Sydney to Tokyo latency and RTT](/docs/network/latency/pairs/syd-tyo-rtt): 101.3 ms
* [Sydney to Taipei latency and RTT](/docs/network/latency/pairs/syd-tpe-rtt): 131.7 ms
* [Sydney to Hong Kong latency and RTT](/docs/network/latency/pairs/syd-hkg-rtt): 135.7 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/syd-jnb.pings.{csv,json,yaml}`. Cite the route, round timestamp and dataset version. Example: "Hats Network latency dataset, Sydney → 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/syd-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.