ICMP RTT measurement results for London, UK, to Johannesburg, South Africa: average latency, jitter, packet loss, distance, and route context.

🇬🇧 London, UK (LON) → 🇿🇦 Johannesburg, South Africa (JNB)

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

The 2026-08-16T04:07:28Z London-to-Johannesburg ICMP echo round returned an average RTT of 179.6 ms, with a minimum of 171.6 ms and a maximum of 203.66 ms across 50 samples. Zero packet loss and 4.3 ms of jitter point to a stable long-haul path, even though the average sits in the 'Fair' latency tier.

At roughly 9,039 km apart, the pair's straight-line vacuum floor is 60.3 ms and its fiber floor is 88.52 ms. The measured RTT is 2.03 times that fiber floor, equal to about 49.3% fiber efficiency; the extra time is consistent with a real cable route longer than the geodesic, not with loss or erratic delay.

Among the 19 outbound routes in this round, this path ranks 16th by average RTT, placing it in the slower half of the source's outbound set. Its standard deviation of 5.96 ms is about 3.32% of the average, close to the round's median variability of 3.28% across the outbound group.

For operators watching London–South Africa latency, the stable, loss-free profile is the more notable result: average delay is less informative than the narrow spread around it. The 2026-08-16T04:07:28Z round shows a route that may be relatively slow among outbound destinations, but it is not a volatile one.

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
Destination Region	Africa

Ping Measurement Series

The chart below renders the 50-sample ICMP echo measurement round for this route; an accessible table of every sample is included with the chart.

Ping series: LON → JNB

50 ICMP echo samples at 100 ms intervals · round 2026-08-16T04:07:28Z · avg 179.6 ± 0.84 ms (SE)

Sample distribution: box = interquartile range (175.6–181.5 ms), median 178.5 ms · whiskers = min–max · diamond = round average · each dot is one measured sample.

How to read this chart

The shaded band spans the measured minimum to maximum RTT of all samples collected up to that point, and the thin line traces the running average. The final position therefore matches the round statistics exactly — the band only widens when a new extreme sample arrives.

The dashed line is the round average, and the shaded band at the bottom is the theoretical fiber-optic floor (88.5 ms) for this route.

Full 50-sample dataset

Seq	Offset (ms)	RTT (ms)
1	0	203.66
2	100	183.26
3	200	190.30
4	300	185.09
5	400	182.78
6	500	175.67
7	600	176.09
8	700	179.12
9	800	178.30
10	900	176.56
11	1000	184.35
12	1100	178.95
13	1200	179.18
14	1300	177.62
15	1400	174.42
16	1500	175.05
17	1600	172.46
18	1700	186.53
19	1800	176.49
20	1900	181.50
21	2000	175.64
22	2100	173.03
23	2200	180.86
24	2300	177.15
25	2400	179.78
26	2500	179.46
27	2600	180.10
28	2700	175.63
29	2800	176.53
30	2900	180.46
31	3000	180.96
32	3100	175.87
33	3200	190.48
34	3300	189.95
35	3400	186.53
36	3500	178.74
37	3600	174.02
38	3700	173.24
39	3800	174.98
40	3900	172.64
41	4000	171.60
42	4100	173.80
43	4200	173.55
44	4300	177.04
45	4400	176.14
46	4500	181.35
47	4600	188.13
48	4700	180.37
49	4800	178.23
50	4900	186.36

Download This Route's Data

This route's measurement round is published as open data (CC BY 4.0) in CSV, JSON, and YAML. See About This Measurement for citation guidance.

Download this dataset

Per-route ICMP ping series, released under CC BY 4.0. Uncompressed plain text — no decompression step needed.

CSV JSON YAML Full dataset

Theoretical Fiber Latency

The public physical reference uses the GeoNames city centres for London (51.50853, -0.12574) and Johannesburg (-26.20227, 28.04363). It does not disclose either facility address.

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 1.33× 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	2.03×

Attenuation is used to estimate the number of 80 km optical spans; it does not directly slow light. See the full theoretical fiber latency, GeoNames, attenuation, and amplifier methodology.

Stability & Trend

The current measurement round (2026-08-16T04:07:28Z) collected 50 ICMP echo samples on this route. Distribution statistics from that round:

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%

RTT trend

Estimated route stability across the selected time window.

Average: 179.7 ms
Minimum: 177.5 ms
Maximum: 181.3 ms
Average loss: 0.02%

Route Context

Departure PoP: London (LON)
Destination PoP: Johannesburg (JNB)
Region overview: Europe → Africa
Full global matrix: Backbone Latency Matrix
Physical methodology: Theoretical Fiber Latency

Reverse direction

Johannesburg to London latency and RTT — 158 ms

Fastest routes departing London (LON)

London to Amsterdam latency and RTT — 5.2 ms
London to Paris latency and RTT — 6.4 ms
London to Frankfurt latency and RTT — 13.6 ms
London to Berlin latency and RTT — 16.2 ms
London to Marseille latency and RTT — 17.9 ms

Fastest routes arriving at Johannesburg (JNB)

Amsterdam to Johannesburg latency and RTT — 171.9 ms
Berlin to Johannesburg latency and RTT — 172.1 ms
Paris to Johannesburg latency and RTT — 180.9 ms
Frankfurt to Johannesburg latency and RTT — 188.4 ms
Marseille to Johannesburg latency and RTT — 198.5 ms

Same corridor (Europe → Africa)

Moscow to Johannesburg latency and RTT — 201.9 ms

About This Measurement

Published RTT reflects best-case backbone path behavior measured with ICMP echo probes between PoPs. End-user latency also depends on local access networks, congestion, routing policy, and traffic engineering. None of these values is an SLA.

The measurement round behind this page is published as open data under CC BY 4.0 in the Hats Network latency dataset. Per-pair files are available at /opendata/latency/latest/pairs/lon-jnb.pings.{csv,json,yaml}. When citing, include the route, the measurement round timestamp, and the dataset version — for example: "Hats Network latency dataset, London → Johannesburg round 2026-08-16T04:07:28Z, CC BY 4.0".

Data auto-generated on August 16, 2026. Explore the full interactive latency matrix or browse more city-pair routes.

London, UK → Johannesburg, South Africa RTT