# London, UK β†’ Johannesburg, South Africa RTT πŸ‡¬πŸ‡§ **London, UK (LON)** β†’ πŸ‡ΏπŸ‡¦ **Johannesburg, South Africa (JNB)** Measurement round: `2026-08-16T04:07:28Z`. London to Johannesburg averaged 179.6 ms, compared with a 88.52 ms city-centre fiber reference. The difference cannot be assigned to a particular cable or carrier from RTT alone. Standard deviation was 5.96 ms, or 3.3% of the average. This describes variation within the sample without identifying its cause. ## Latency Summary | Metric | Value | | -------------------- | ---------------------------------------------- | | RTT | **179.6 ms** | | Jitter | **4.3 ms** | | Packet Loss | **0%** | | Standard Fiber Floor | **88.52 ms** | | Fiber Efficiency | **49.3%** | | Latency Tier | Fair | | Source Region | [Europe](/docs/network/latency/regions/europe) | | 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: [London](https://www.geonames.org/2643743) (51.50853, -0.12574) 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 | **9,039.3 km** | | Vacuum RTT floor | **60.3 ms** | | Standard fiber RTT floor ($n_g=1.4679$) | **88.52 ms** | | Low-latency fiber material floor | **88.16 ms** | | Engineering floor (5% path allowance) | **92.96 ms** | | Research 1.33Γ— mapped-fiber reference | **117.73 ms** | | Estimated unamplified path loss | **1898.3 dB** | | Transparent optical spans / inline amplifiers | **119 / 118** | | Published RTT inflation over fiber floor | **2.03Γ—** | 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 | **171.6 ms** | | Average RTT | **179.6 ms** | | Maximum RTT | **203.66 ms** | | Standard deviation | **5.96 ms** | | Stdev / average | **3.3%** | ## Route Context * Departure PoP: [London (LON)](/docs/network/latency/lon-london) * Destination PoP: [Johannesburg (JNB)](/docs/network/latency/jnb-johannesburg) * Region overview: [Europe](/docs/network/latency/regions/europe) β†’ [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 London latency and RTT](/docs/network/latency/pairs/jnb-lon-rtt): 158 ms **Fastest routes departing London (LON)** * [London to Amsterdam latency and RTT](/docs/network/latency/pairs/lon-ams-rtt): 5.2 ms * [London to Paris latency and RTT](/docs/network/latency/pairs/lon-par-rtt): 6.4 ms * [London to Frankfurt latency and RTT](/docs/network/latency/pairs/lon-fra-rtt): 13.6 ms * [London to Berlin latency and RTT](/docs/network/latency/pairs/lon-ber-rtt): 16.2 ms * [London to Marseille latency and RTT](/docs/network/latency/pairs/lon-mrs-rtt): 17.9 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 * [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 * [Marseille to Johannesburg latency and RTT](/docs/network/latency/pairs/mrs-jnb-rtt): 198.5 ms **Same corridor (Europe β†’ Africa)** * [Moscow to Johannesburg latency and RTT](/docs/network/latency/pairs/mow-jnb-rtt): 201.9 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/lon-jnb.pings.{csv,json,yaml}`. Cite the route, round timestamp and dataset version. Example: "Hats Network latency dataset, London β†’ 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).* --- ## License and attribution - **Canonical source:** [View the human-readable HTML page](https://hatsnet.io/docs/network/latency/pairs/lon-jnb-rtt). - **Original documentation:** Β© Hats Network Inc., licensed under [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/). - **Public latency data:** Β© 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) β€” includes attribution requirements, third-party material, trademarks, source code and other exclusions.