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

🇺🇸 Ashburn, USA (IAD) → 🇯🇵 Tokyo, Japan (TYO)

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

Ashburn to Tokyo averaged 141.9 ms across 50 replies. The observed range was 136.1 to 154.55 ms; these figures describe one probe round, not a long-term service target.

Standard deviation was 4.32 ms, or 3.0% of the average. This describes variation within the sample without identifying its cause.

Latency Summary

Metric	Value
RTT	141.9 ms
Jitter	3.99 ms
Packet Loss	0%
Standard Fiber Floor	106.69 ms
Fiber Efficiency	75.2%
Latency Tier	Good
Source Region	North America
Destination Region	Asia Pacific

Ping Measurement Series

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

Ping series: IAD → TYO

50 ICMP echo samples at 100 ms intervals · round 2026-08-16T04:07:28Z · avg 141.9 ± 0.61 ms (SE)

Sample distribution: box = interquartile range (138.7–144.8 ms), median 140.5 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 (106.7 ms) for this route.

Full 50-sample dataset

Seq	Offset (ms)	RTT (ms)
1	0	136.10
2	100	142.14
3	200	139.00
4	300	139.11
5	400	137.90
6	500	151.25
7	600	148.65
8	700	141.13
9	800	145.55
10	900	145.27
11	1000	139.06
12	1100	137.13
13	1200	138.10
14	1300	137.14
15	1400	147.99
16	1500	144.65
17	1600	141.47
18	1700	137.83
19	1800	138.54
20	1900	140.75
21	2000	139.91
22	2100	139.66
23	2200	137.23
24	2300	138.53
25	2400	139.17
26	2500	137.43
27	2600	137.53
28	2700	139.10
29	2800	147.20
30	2900	140.23
31	3000	147.19
32	3100	140.77
33	3200	142.98
34	3300	141.54
35	3400	142.14
36	3500	146.42
37	3600	151.26
38	3700	141.45
39	3800	137.72
40	3900	140.02
41	4000	139.95
42	4100	154.55
43	4200	144.88
44	4300	138.75
45	4400	139.82
46	4500	145.28
47	4600	143.55
48	4700	150.04
49	4800	143.21
50	4900	138.73

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: Ashburn (39.04372, -77.48749) and Tokyo (35.68950, 139.69171). These are not facility coordinates or a surveyed cable path.

Physical Reference	Value
WGS-84 geodesic distance	10,894.6 km
Vacuum RTT floor	72.68 ms
Standard fiber RTT floor ( $n_g=1.4679$ )	106.69 ms
Low-latency fiber material floor	106.26 ms
Engineering floor (5% path allowance)	112.04 ms
Research 1.33× mapped-fiber reference	141.9 ms
Estimated unamplified path loss	2287.9 dB
Transparent optical spans / inline amplifiers	143 / 142
Published RTT inflation over fiber floor	1.33×

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	136.1 ms
Average RTT	141.9 ms
Maximum RTT	154.55 ms
Standard deviation	4.32 ms
Stdev / average	3.0%

Estimated RTT trend

Modeled comparison, not historical probe measurements.

Average: 142.0 ms
Minimum: 140.7 ms
Maximum: 143.4 ms
Average loss: 0.02%

Route Context

Departure PoP: Ashburn (IAD)
Destination PoP: Tokyo (TYO)
Region overview: North America → Asia Pacific
Corridor overview: North America to Asia Pacific
Full global matrix: Backbone Latency Matrix
Physical methodology: Theoretical Fiber Latency

Reverse direction

Tokyo to Ashburn latency and RTT: 142.9 ms

Fastest routes departing Ashburn (IAD)

Ashburn to New York latency and RTT: 6 ms
Ashburn to Miami latency and RTT: 27.4 ms
Ashburn to Los Angeles latency and RTT: 60.7 ms
Ashburn to Seattle latency and RTT: 62.3 ms
Ashburn to London latency and RTT: 70.3 ms

Fastest routes arriving at Tokyo (TYO)

Taipei to Tokyo latency and RTT: 31.9 ms
Hong Kong to Tokyo latency and RTT: 44.9 ms
Singapore to Tokyo latency and RTT: 68.9 ms
Seattle to Tokyo latency and RTT: 85 ms
Los Angeles to Tokyo latency and RTT: 101.2 ms

Same corridor (North America → Asia Pacific)

Seattle to Taipei latency and RTT: 114.7 ms
Seattle to Hong Kong latency and RTT: 130.4 ms
Los Angeles to Taipei latency and RTT: 132.9 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. Per-pair files are available at /opendata/latency/latest/pairs/iad-tyo.pings.{csv,json,yaml}. Cite the route, round timestamp and dataset version. Example: "Hats Network latency dataset, Ashburn → Tokyo 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.

Ashburn, USA → Tokyo, Japan RTT