Explore Tokyo, Japan to London, UK ICMP RTT, jitter, packet loss and fiber latency limits on the AS203314 network. View route data.

🇯🇵 Tokyo, Japan (TYO) → 🇬🇧 London, UK (LON)

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

Tokyo to London averaged 202.7 ms, compared with a 93.84 ms city-centre fiber reference. The difference cannot be assigned to a particular cable or carrier from RTT alone.

Standard deviation was 5.6 ms, or 2.8% of the average. This describes variation within the sample without identifying its cause.

Latency Summary

Metric	Value
RTT	202.7 ms
Jitter	4.9 ms
Packet Loss	0%
Standard Fiber Floor	93.84 ms
Fiber Efficiency	46.3%
Latency Tier	Fair
Source Region	Asia Pacific
Destination Region	Europe

Ping Measurement Series

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

Ping series: TYO → LON

50 ICMP echo samples at 100 ms intervals · round 2026-08-16T04:07:28Z · avg 202.7 ± 0.79 ms (SE)

Sample distribution: box = interquartile range (198.9–204.1 ms), median 201.6 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 (93.8 ms) for this route.

Full 50-sample dataset

Seq	Offset (ms)	RTT (ms)
1	0	199.39
2	100	206.75
3	200	204.14
4	300	224.34
5	400	208.54
6	500	205.03
7	600	199.13
8	700	198.33
9	800	196.84
10	900	198.84
11	1000	203.99
12	1100	204.41
13	1200	203.93
14	1300	201.10
15	1400	211.87
16	1500	207.98
17	1600	203.34
18	1700	212.08
19	1800	202.49
20	1900	199.07
21	2000	196.86
22	2100	199.51
23	2200	196.94
24	2300	205.09
25	2400	218.83
26	2500	203.85
27	2600	201.95
28	2700	198.73
29	2800	199.07
30	2900	196.60
31	3000	203.92
32	3100	202.62
33	3200	200.57
34	3300	198.82
35	3400	207.54
36	3500	202.11
37	3600	202.80
38	3700	199.78
39	3800	201.32
40	3900	197.63
41	4000	198.45
42	4100	197.84
43	4200	197.03
44	4300	213.21
45	4400	202.10
46	4500	199.95
47	4600	196.92
48	4700	200.45
49	4800	202.65
50	4900	200.27

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 London (51.50853, -0.12574). These are not facility coordinates or a surveyed cable path.

Physical Reference	Value
WGS-84 geodesic distance	9,582.1 km
Vacuum RTT floor	63.93 ms
Standard fiber RTT floor ( $n_g=1.4679$ )	93.84 ms
Low-latency fiber material floor	93.46 ms
Engineering floor (5% path allowance)	98.54 ms
Research 1.33× mapped-fiber reference	124.8 ms
Estimated unamplified path loss	2012.2 dB
Transparent optical spans / inline amplifiers	126 / 125
Published RTT inflation over fiber floor	2.16×

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	196.6 ms
Average RTT	202.7 ms
Maximum RTT	224.34 ms
Standard deviation	5.6 ms
Stdev / average	2.8%

Estimated RTT trend

Modeled comparison, not historical probe measurements.

Average: 202.7 ms
Minimum: 200.4 ms
Maximum: 204.7 ms
Average loss: 0.02%

Route Context

Departure PoP: Tokyo (TYO)
Destination PoP: London (LON)
Region overview: Asia Pacific → Europe
Full global matrix: Backbone Latency Matrix
Physical methodology: Theoretical Fiber Latency

Reverse direction

London to Tokyo latency and RTT: 202.9 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 London (LON)

Amsterdam to London latency and RTT: 5.2 ms
Paris to London latency and RTT: 6.4 ms
Frankfurt to London latency and RTT: 12.9 ms
Berlin to London latency and RTT: 15.2 ms
Marseille to London latency and RTT: 18.9 ms

Same corridor (Asia Pacific → Europe)

Hong Kong to Moscow latency and RTT: 118.2 ms
Taipei to Moscow latency and RTT: 132.7 ms
Singapore to Marseille latency and RTT: 140.6 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-lon.pings.{csv,json,yaml}. Cite the route, round timestamp and dataset version. Example: "Hats Network latency dataset, Tokyo → London 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 → London, UK RTT