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Welcome to GeoTorrent.org!
Our goal is to provide fast peer-to-peer sharing of geospatial data.
Before you go any further you should read the GeoTorrent.org user agreement.
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GeoTorrent.org information
What types of data are shared?
All different types of geospatial data is shared here. For example Air and satellite photo's, as well as attribute data.
What formats is the data in?
Imagery is in either ECW or JPEG 2000 format. Both formats allow high levels of compression. For example 1 terabyte (1,000 gigabytes) of raw data can be compressed to just 50 GB. JPEG 2000 also provides a lossless compression algorithm, allowing for pixel-for-pixel fidelity with the original dataset.
Attribute (vector) data can be distributed in any common data format e.g. shape, tab files or native data formats.
How can i read the data?
Many common GIS applications already read ECW and JPEG 2000 image files. Of particular note is ER Viewer, a free reader of these formats. A list of software that supports these formats can be found at http://www.ermapper.com/downloads/.
Various other GIS applications can be used to read the attribute data.
What is this bittorrent all about anyway? How do I get the files?
Bittorrent is a peer-to-peer file sharing system that avoids the bandwidth bottlenecks found in other file distribution systems. To access the data on geoTorrent.org you will need a bittorrent client such as Azureus to download the data.
For more general bittorrent information check out Brian's BitTorrent FAQ and Guide.
How do i upload new data to geoTorrent.org?
You must be an authorised 'uploader' to share new material on geoTorrent.org. If you would like to be an uploader, please contact us.
The datasets you want to share must be available for mass-distribution (free from prohibitive copyrights, etc) and must be in a data format support by geoTorrent.org .
Instructions on how to create, upload and seed a new torrent are found here.
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User information
I registered an account but did not receive the confirmation e-mail!
You can use this form to delete the account so you can re-register.
Note though that if you didn't receive the email the first time it will probably not
succeed the second time either so you should really try another email address.
I've lost my user name or password! Can you send it to me?
Please use this form to have the login details mailed back to you.
Can you rename my account?
We do not rename accounts. Please create a new one. (Use this form to
delete your present account.)
Can you delete my (confirmed) account?
You can do it yourself by using this form.
Why is my IP displayed on my details page?
Only you and the site moderators can view your IP address and email. Regular users do not see that information.
Help! I cannot login!? (a.k.a. Login of Death)
This problem sometimes occurs with MSIE. Close all Internet Explorer windows
and open Internet Options in the control panel. Click the Delete Cookies button.
You should now be able to login.
Why is my port number reported as "---"? (And why should I care?)
The tracker has determined that you are firewalled or NATed and cannot accept incoming connections.
This means that other peers in the swarm will be unable to connect to you, only you to them. Even worse,
if two peers are both in this state they will not be able to connect at all. This has obviously a
detrimental effect on the overall speed.
The way to solve the problem involves opening the ports used for incoming connections
(the same range you defined in your client) on the firewall and/or configuring your
NAT server to use a basic form of NAT
for that range instead of NAPT (the actual process differs widely between different router models.
Check your router documentation and/or support forum. You will also find lots of information on the
subject at PortForward).
How do I add an avatar to my profile?
First, find an image that you like, and that is within the
rules. Then you will have
to find a place to host it, such as our own BitBucket.
(Other popular choices are Photobucket,
Upload-It! or
ImageShack).
All that is left to do is copy the URL you were given when
uploading it to the avatar field in your profile.
Please do not make a post just to test your avatar. If everything is allright you'll see it
in your details page.
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Downloading
How do I resume a broken download or reseed something?
Open the .torrent file. When your client asks you for a location, choose the location of
the existing file(s) and it will resume/reseed the torrent.
What are these "a piece has failed an hash check" messages?
Bittorrent clients check the data they receive for integrity. When a piece fails this check it is
automatically re-downloaded. Occasional hash fails are a common occurrence, and you shouldn't worry.
Some clients have an (advanced) option/preference to 'kick/ban clients that send you bad data' or
similar. It should be turned on, since it makes sure that if a peer repeatedly sends you pieces that
fail the hash check it will be ignored in the future.
The torrent is supposed to be 100MB. How come I downloaded 120MB?
See the hash fails topic. If your client receives bad data it will have to redownload it, therefore
the total downloaded may be larger than the torrent size. Make sure the "kick/ban" option is turned on
to minimize the extra downloads.
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How can I improve my download speed?
The download speed mostly depends on the seeder-to-leecher ratio (SLR). Poor download speed is
mainly a problem with new and very popular torrents where the SLR is low.
(Proselytising sidenote: make sure you remember that you did not enjoy the low speed.
Seed so that others will not endure the same.)
There are a couple of things that you can try on your end to improve your speed:
Do not immediately jump on new torrents
In particular, do not do it if you have a slow connection. The best speeds will be found around the
half-life of a torrent, when the SLR will be at its highest. (The downside is that you will not be able to seed
so much. It's up to you to balance the pros and cons of this.)
Make yourself connectable
See the Why is my port listed as "---" section.
Limit your upload speed
The upload speed affects the download speed in essentially two ways:
- Bittorrent peers tend to favour those other peers that upload to them. This means that if A and B
are leeching the same torrent and A is sending data to B at high speed then B will try to reciprocate.
So due to this effect high upload speeds lead to high download speeds.
- Due to the way TCP works, when A is downloading something from B it has to keep telling B that
it received the data sent to him. (These are called acknowledgements - ACKs -, a sort of "got it!" messages).
If A fails to do this then B will stop sending data and wait. If A is uploading at full speed there may be no
bandwidth left for the ACKs and they will be delayed. So due to this effect excessively high upload speeds lead
to low download speeds.
The full effect is a combination of the two. The upload should be kept as high as possible while allowing the
ACKs to get through without delay. A good thumb rule is keeping the upload at about 80% of the theoretical
upload speed. You will have to fine tune yours to find out what works best for you. (Remember that keeping the
upload high has the additional benefit of helping with your ratio.)
If you are running more than one instance of a client it is the overall upload speed that you must take into account.
Some clients (e.g. Azureus) limit global upload speed, others (e.g. Shad0w's) do it on a per torrent basis.
Know your client. The same applies if you are using your connection for anything else (e.g. browsing or ftp),
always think of the overall upload speed.
Limit the number of simultaneous connections
Some operating systems (like Windows 9x) do not deal well with a large number of connections, and may even crash.
Also some home routers (particularly when running NAT and/or firewall with stateful inspection services) tend to become
slow or crash when having to deal with too many connections. There are no fixed values for this, you may try 60 or 100
and experiment with the value. Note that these numbers are additive, if you have two instances of
a client running the numbers add up.
Limit the number of simultaneous uploads
Isn't this the same as above? No. Connections limit the number of peers your client is talking to and/or
downloading from. Uploads limit the number of peers your client is actually uploading to. The ideal number is
typically much lower than the number of connections, and highly dependent on your (physical) connection.
Just give it some time
As explained above peers favour other peers that upload to them. When you start leeching a new torrent you have
nothing to offer to other peers and they will tend to ignore you. This makes the starts slow, in particular if,
by change, the peers you are connected to include few or no seeders. The download speed should increase as soon
as you have some pieces to share.
Why is my browsing so slow while leeching?
Your download speed is always finite. If you are a peer in a fast torrent it will almost certainly saturate your
download bandwidth, and your browsing will suffer. At the moment there is no client that allows you to limit the
download speed, only the upload. You will have to use a third-party solution,
such as NetLimiter.
Browsing was used just as an example, the same would apply to gaming, IMing, etc...
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What if I can't find the answer to my problem here?
Post in the Forums, by all means. You'll find they
are usually a friendly and helpful place,
provided you follow a few basic guidelines:
- Make sure your problem is not really in this FAQ. There's no point in posting just to be sent
back here.
- Before posting read the sticky topics (the ones at the top). Many times new information that
still hasn't been incorporated in the FAQ can be found there.
- Help us in helping you. Do not just say "it doesn't work!". Provide details so that we don't
have to guess or waste time asking. What client do you use? What's your OS? What's your network setup? What's the exact
error message you get, if any? What are the torrents you are having problems with? The more
you tell the easiest it will be for us, and the more probable your post will get a reply.
- And needless to say: be polite. Demanding help rarely works, asking for it usually does
the trick.
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