Network Engineering Stack Exchange is a question and answer site for network engineers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I just read news that:

NSA stores 80% of all phone calls from:

Many fiber-optic cables do go through the US, but would my data end up there even if it was supposed to go to somewhere before it reaches the US?(Example: Japan to UK)

I believe the cable used is the "FLAG" cable.(Correct if I am wrong)

share|improve this question

closed as off-topic by some_guy_long_gone, generalnetworkerror, Adam Loveless, Mike Pennington Jul 13 '14 at 9:30

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "NE is a site for network professionals to ask and provide answers about professional networks. Your question falls outside the areas our community decided are on topic. Please see What topics can I ask about here? for more details. If you disagree with this closure, please ask on meta." – some_guy_long_gone, generalnetworkerror, Adam Loveless, Mike Pennington
If this question can be reworded to fit the rules in the help center, please edit the question.

up vote 6 down vote accepted

I’m going to try not to turn this post into a doomsday prophecy.

The thing that needs to be noted up front is that the US sends/receives a large percentage of the global voice traffic. Below is a map of how these calls look globally. Notice the huge red lines coming out of every side of the US.

Global Voice Traffic Map 2010

Image curtesy of TeleGeography - Global Voice Traffic Map 2010.

And since all US based companies are obligated to comply with Federal requests (National Security Letters ). This means, yes that is likely possible for calls to/from the US.

VoIP might be a whole different technology, but still just as vulnerable. Carriers will usually have to comply with the same data retention policies as TDM phones. Technology companies like Skype are pretty much in the same boat. Since the NSA is relatively fond of infrastructure attacks and traffic interception is a thing, I would put my money on them having a technique that hijacks remote routes and redirects networks through agency controlled autononous systems.

So in your instance, from Japan to UK, unless the NSA was tapping international sea lines, they would be unlikely to obtain this information. But the problem is that they do.

share|improve this answer
One might argue that part of the reason so much voip goes through the US is that we're a nation full of immigrants; many of them call home... a lot. E Pluribus Unum – Mike Pennington Jul 13 '14 at 12:59
lol come to UK or even Europe and that argument may drop Mike. Thanks Ryan. – Damien Golding Jul 13 '14 at 13:54
One thing I am still wondering about is how data is relayed on. Normally, I would guess that there would be location metadata that means if the data doesn't need to go further it doesn't, but not sure. It's a bit worrying if data just flows on to places like the US :/ – Damien Golding Jul 13 '14 at 14:00
@DamienGolding, I've spent quite a bit of time in Europe. Perhaps you'd like to check the UN immigration stats before laughing: The US gained the largest absolute number of international migrants between 1990 and 2013—nearly 23 million, equal to one million additional migrants per year. – Mike Pennington Jul 13 '14 at 17:46

I agree with JDGray that this question may not be within the scope of the forum, but it's a teachable moment, so:

Use the tool traceroute (also called tracert on Windows) to identify the path your traffic takes. (Your packets may take one path on their way to the destination, and a different path on the way back to you, the source, but for a minute we'll ignore asymmetric routing.)

On your Mac, open Terminal; on a Windows machine, from the Start Menu, select Run and type "cmd" to open a Command Window.

You'll be a prompt, like mac$ or c:\> and at this prompt, type:


(Or, tracert.)

You'll see output like this, with some of the lines removed for brevity:

traceroute to (, 64 hops max, 52 byte packets
 9 (  18.563 ms  14.462 ms  20.606 ms
 10 (  176.588 ms * *
 11 (  190.971 ms * *
 12 (  184.038 ms  206.667 ms *
 13 (  176.868 ms  197.523 ms *
 17 (  184.593 ms  177.496 ms  182.139 ms
 22 (  184.533 ms  171.511 ms  171.454 ms

Generally, while a lot of it may be nonsense at first glance, you can pick out an approximate geographic location just by looking at the city names on the left: you can see my test to Oxford passed from SoCal to NorCal, over to New York, back across the river to New Jersey, and then across to London and Reading before heading up to Oxford's network.

On the right side we have the "round-trip time" of each packet, which because fiber optic cable is transmitting light, can be roughly gauged by considering light travels to a mirror and reflects back to you at speeds of 300km in 2ms, or 1000M in 10ms. So we can estimate distance (after acknowledging there are numerous computers in the middle running software to process everything, so they add delay.) This is a bad example, because the links are slow to reply to the trace route, but you can see I'm fairly close to Los Angeles. The trip up to San Francisco should be about 10ms more under normal conditions. Then across the continent is 60-80ms. Across the ocean is another 60-80ms. In the real world all the routers in middle cut the speed in half from the theoretical max.

In short, run a traceroute to the hosts you use and see where the traffic goes. Beware that's a technical answer to a leading question; if you're concerned about state-sponsored surveillance of the Internet, you should be mindful of every government and every location where a ship's anchor has accidentally severed undersea cables. In our daily lives, we're more likely to encounter employer-based surveillance. Use S/MIME and TLS anyway.

share|improve this answer
This deserves a +1 but can't without 15 rep :/ Tried it out and it seems many UK sites end up going through the US... dodgy. – Damien Golding Jul 13 '14 at 13:57
traceroute is a layer-3 tool. As such, it cannot tell you much about the path of a physical circuit. (eg. an ATM DSL circuit who's hops via traceroute are CA then NC.) Also, traceroute cannot tell you jack about a TDM (voice) path. VoIP... you cannot know what happens to it once it's delivered to your provider. – Ricky Beam Jul 13 '14 at 19:01

I would imagine that is is all dependent on what route the data takes in getting to it's destination. Also, there is always the possibility that the NSA does not require the data to transit through the USA proper in order to be retained. However, I don't know that this particular questuion is within the scope of this forum.

share|improve this answer

Not the answer you're looking for? Browse other questions tagged or ask your own question.