Explore Tokyo, Japan to Johannesburg, South Africa ICMP RTT, jitter, packet loss and fiber latency limits on the AS203314 network.

🇯🇵 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
Destination Region	Africa

Ping Measurement Series

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

Ping series: TYO → JNB

50 ICMP echo samples at 100 ms intervals · round 2026-08-16T04:07:28Z · avg 359.2 ± 2.23 ms (SE)

Sample distribution: box = interquartile range (347.0–367.8 ms), median 357.3 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 (132.6 ms) for this route.

Full 50-sample dataset

Seq	Offset (ms)	RTT (ms)
1	0	341.54
2	100	339.80
3	200	386.20
4	300	369.90
5	400	353.47
6	500	367.98
7	600	350.77
8	700	361.45
9	800	347.32
10	900	381.99
11	1000	407.64
12	1100	366.33
13	1200	372.96
14	1300	359.05
15	1400	351.45
16	1500	350.76
17	1600	344.29
18	1700	411.36
19	1800	371.88
20	1900	374.65
21	2000	369.56
22	2100	352.38
23	2200	346.08
24	2300	355.42
25	2400	355.45
26	2500	352.28
27	2600	343.57
28	2700	341.58
29	2800	343.25
30	2900	340.55
31	3000	382.35
32	3100	360.89
33	3200	361.99
34	3300	346.95
35	3400	344.66
36	3500	350.66
37	3600	359.12
38	3700	368.26
39	3800	374.41
40	3900	359.97
41	4000	350.23
42	4100	353.01
43	4200	344.01
44	4300	340.61
45	4400	339.59
46	4500	364.30
47	4600	359.49
48	4700	362.20
49	4800	367.19
50	4900	359.20

Download This Route's Data

Download the probe round as CSV, JSON or YAML under CC BY 4.0. Citation details include the route and round timestamp.

CSV JSON YAML Full dataset

Theoretical Fiber Latency

The propagation model uses public city-centre coordinates from GeoNames: Tokyo (35.68950, 139.69171) and Johannesburg (-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.

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%

Estimated RTT trend

Modeled comparison, not historical probe measurements.

Average: 359.2 ms
Minimum: 356.2 ms
Maximum: 361.8 ms
Average loss: 0.02%

Route Context

Departure PoP: Tokyo (TYO)
Destination PoP: Johannesburg (JNB)
Region overview: Asia Pacific → Africa
Full global matrix: Backbone Latency Matrix
Physical methodology: Theoretical Fiber Latency

Reverse direction

Johannesburg to Tokyo latency and RTT: 360.5 ms

Fastest routes departing Tokyo (TYO)

Tokyo to Taipei latency and RTT: 32.3 ms
Tokyo to Hong Kong latency and RTT: 44.8 ms
Tokyo to Singapore latency and RTT: 69.4 ms
Tokyo to Seattle latency and RTT: 84.8 ms
Tokyo to Los Angeles latency and RTT: 101.2 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
London to Johannesburg latency and RTT: 179.6 ms
Paris to Johannesburg latency and RTT: 180.9 ms
Frankfurt to Johannesburg latency and RTT: 188.4 ms

Same corridor (Asia Pacific → Africa)

Singapore to Johannesburg latency and RTT: 312.6 ms
Hong Kong to Johannesburg latency and RTT: 316.7 ms
Taipei to Johannesburg latency and 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. 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 or browse more city-pair routes.

Tokyo, Japan → Johannesburg, South Africa RTT