Computing desk
< January 27	<< Dec \| January \| Feb >>	January 29 >

Welcome to the Wikipedia Computing Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

January 28

Brazil hub for trans-atlantic traffic?

In reporting surrounding the US spying scandal and Brazil, lots of sources like [1] [2] [3] [4] say that Brazil is an important hub for trans-atlantic internet traffic. This includes sources like [5] [6] [7] which talk about the importance of Brazil as a trans-atlantic hub, then also talk about how they want to have more cables to bypass the US.

Anyway the claim sounded a bit strange, from searching it sounds like this claim came from this New Yorker article. From the map / source they used to support this claim [8] there is a grand total of 1 trans-atlantic cable systems connecting to Brazil first, Atlantis-2, which connects to Africa and goes on to connect to Europe (Portugal). And if the map is accurate and I think it is (from what I've read and also the fact an Argentinian company was involved), it looks like Argentinian traffic doesn't have to go through Brazil.

More details from sources, not that important

There are also 2 proposed systems, South Atlantic Cable System and South Atlantic Express which will connect to Africa (and may go on to connect to Asia). Not shown on that map, but another proposal is WASACE (cable system). (It's possible the spying scandal will be added impetus for such cable systems although I think all of these were annouced well before the spying scandal.)

However much the Brazil teleco quoted by New Yorker may claim importance, Atlantis-2 if our article is still accurate, has a installed capacity of 40 Gb/s. According to [9], total trans-atlantic capacity is about 40Tb/s so it's about 1/1000 of the total. In terms of Brazil, I think their total capacity is probably well over by now 1 Tb/s [10] [11]. Even in terms of African international traffic, it doesn't sound like it's the most significant cable [12].

Is there something I'm missing or am I right that when all these sources say Brazil is an important hub for trans-atlantic hub, all they're really referring to is a single 40 Gb/s cable system and perhaps the cable systems under construction (and likelihood of future cables)? I am assuming when they say trans-atlantic, they're referring to crossings between the Atlantic ocean from the Americas to Europe or Africa, not crossings from North to South America, although of course trans-atlantic connections to other parts of South America may go to Brazil first as with US (and other) ones.

Further explaination of my question

I'm aware of course that Atlantis-2 does have some importance and is also strategic. Particularly since it allows some African, Asian and European to bypass the US and also for low-latency commucations between Africa and perhaps parts of Asia and South America. And the new cables will extend that and geography and strategic significance means Brazil is the likely choice for most trans-atlantic cables between Africa and South America. And it may be that Atlantis-2 is already the most important cable for certain countries (I think I read South Africa somewhere but I'm not sure). So I'm not going to get in to semantics about whether the 'important hub' bit is right or wrong here (personally I would use emerging hub or something but that's ultimately OT for the RD). I just wanted to check I wasn't missing something.

Nil Einne (talk) 03:23, 28 January 2014 (UTC)[reply]

'Drawing' Kanji on Linux

Is there a way, similar to Microsoft's IME Pad for Japanese, to 'draw' the kanji, so that it gives you a copypastable version? Not knowing the pronunciation of the kanji, it's impossible to type it. I am using Anthy on Linux Mint, but that does not offer the same thing. KägeTorä - (影虎) (TALK) 10:51, 28 January 2014 (UTC)[reply]

Could you use an online service like [[13]]? It works for every OS, including smartphones. OsmanRF34 (talk) 19:00, 28 January 2014 (UTC)[reply]

Technically, I think "copypastable" can get very complicated very quickly. I just copied this character: 下 from Osman's link. But I'm not entirely sure that the character encoding is fully portable. I'm also not sure whether all readers will see it rendered properly. Consider e.g. here [14], which shows dozens of ways of encoding that character. Maybe every application you use has full unicode support; I just wanted to warn of potential problems with pasting "special" characters. SemanticMantis (talk) 21:39, 28 January 2014 (UTC)[reply]

That's right, but it's independent how you obtained the character. The web-page above lets you find the Unicode, and that's the most precise you can get. How readers of a document deal with it is a different story. OsmanRF34 (talk) 00:36, 29 January 2014 (UTC)[reply]

File permissions in Android

Hi, on my Android tablet there is a File Manager widget called "My Files" which shows the user-visible file structure on the non-removable storage ("Root" with subfolders "Alarms", "Android", "Download", "Movies", etc. etc.) I have been trying, so far with little success, to discover what, if anything, controls apps' access to the files stored here. Or do all apps automatically have permission to access this whole file structure without asking for any particular permission? (I am aware that apps can also have their own private files that are not even visible through File Managers. I am not asking about those files, only about the ones in the user-visible file structure that I see via the "My Files" thing.) If anyone can provide any definite information about this, I would be most grateful. Thanks. 86.160.220.253 (talk) 23:44, 28 January 2014 (UTC)[reply]

That's a tricky question. On older versions of Android the permission READ_EXTERNAL_STORAGE was automatically granted. ("External" is a misnomer. It also refers to device storage not specifically allocated to the app.) On the current version ("KitKat"), this permission is required to view the file system. However, I beleive that in most cases older apps don't need the permission even on KitKat phones.

Short answer : Yes. Most apps could read those files without special permissions.

Could they write to those files? Probably not. Except on really old versions of android they'll require WRITE_EXTERNAL_STORAGE to mess with those files.

APL (talk) 00:04, 29 January 2014 (UTC)[reply]

Thanks for your reply APL. When I look at an example app, such as Polaris Office, that can both read from and write to this storage, I see no permissions that seem to correspond to READ_EXTERNAL_STORAGE or WRITE_EXTERNAL_STORAGE. The only storage-related permission is "modify/delete SD card contents", which I have been assuming is not applicable to non-removable storage. Even the "My Files" app itself appears to have no relevant permissions. ... Unless "modify/delete SD card contents" is another misnomer and it DOES actually include this onboard storage?? This is Android 4.0.4. That wouldn't be what you class as a "really old" version would it? Or would it? 86.160.220.253 (talk) 00:53, 29 January 2014 (UTC)[reply]

I believe that the "modify/delete SD card contents" is a "user friendly" name for the WRITE_EXTERNAL_STORAGE permission. But I can't seem to find a comprehensive list that matches the true names of the permissions with how they're displayed to the user.

So yea, that's confusing. APL (talk) 15:19, 29 January 2014 (UTC)[reply]

Thank you. If true, this is the most appalling f***-up by the designers of this system. Even photographs get stored by default to that area. So that app written by some unknown spotty teenager in his bedroom that I just downloaded, thinking it couldn't do any harm because of Android's oh-so-wonderful permissioning system, gets to rifle through all my stuff and send it Christ knows where, just because I didn't care that it could access SD cards because I never use them? Terrific, thanks Android. 86.160.216.98 (talk) 18:34, 29 January 2014 (UTC)[reply]

Any program you run on Windows, Linux, or Mac OS can rifle through all of your personal files, modify or delete them, and, unless you've configured a firewall to block outgoing network connections, send them to who knows where. And sniff all your keystrokes. The Android security model isn't great, but it's better than the largely useless OS security models that we've been stuck with for decades. On Android you can use an iptables frontend like DroidWall to block network access conveniently. -- BenRG (talk) 06:21, 1 February 2014 (UTC)[reply]

The difference is that with Windows etc. you know that everything is open, and take the appropriate extreme care about downloading software. Android is presented as a safe environment, where one can download all kinds of fun stuff with no risk, provided one looks at the permissions that an app requires. Shocking loopholes, such as the fact that any app can look at all your photos without your knowledge or permission (I still find it unbelievable that this could be true) are all the more troubling. 86.160.223.11 (talk) 14:01, 1 February 2014 (UTC)[reply]

Battery on Laptop

If you have a completely depleted battery, as in, the computer has been on constantly (plugged in) for two years and has hardly ever been switched off, can this have an influence on the CPU? I am getting 100% CPU usage on mine, and this has coincided with the fact that the computer tells me the battery is dead. KägeTorä - (影虎) (TALK) 23:47, 28 January 2014 (UTC)[reply]

Modern laptop batteries are computers in themselves, and do communicate with the OS. So it's a theoretical possibility. But in practice, I'd say "No, it's a coincidence". --Stephan Schulz (talk) 00:07, 29 January 2014 (UTC)[reply]

You can just remove the main battery (it's dead anyway) and see how the computer deals with it. I suppose both problems are not related. OsmanRF34 (talk) 00:40, 29 January 2014 (UTC)[reply]

If you download Process Explorer you might discover what has grabbed the CPU's interest. I take it that your operating system is not Apple nor Linux as they don't seem to suffer these problems.--Aspro (talk) 01:44, 29 January 2014 (UTC)[reply]

Depending on what's doing it, you might be able to see in Task Manager as well. - Purplewowies (talk) 08:13, 1 February 2014 (UTC)[reply]