File upload/download using UDP

We have web based j2ee application which allows file upload/download. Due to latency issue upload/download is slower for many users.

1) I read that sending data using UDP can improve data transfer spe开发者_运维知识库ed. How can we send file data using UDP?

2) We are zipping file using GZIP before upload/download to reduce amount data transfer. Is there better method available improve data compression?

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UDP is a protocol that does not guarantee the arrival of messages. You are most likely using a standard file transfer protocol like ftp which should suit you fine. Are your issues with latency or with bandwidth? You might be better of investigating why the link has a high latency or bandwidth issues, as this could prove to be an issue with other parts of your web application.

GZIP and other zipping tools are good for reducing the amount of data that is sent if you're willing up put up with the initial cost of compressing. These tools should have options so you can tweak the level of compression (i.e. take a long amount of time and compress optimally, or compress it quickly but have a larger zipped file). You will probably need to experiment and see what balance works the best for you.

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1) Are there protocols faster than TCP on high latency links?

Yes, UDT is the primary example, but it is not a free trade, for instance consider you now need a custom frontend application to download files.

2) Is there better file compression than GZIP?

Yes, view the exhaustive list at http://www.maximumcompression.com/index.html, bzip2 and 7-zip are popular alternatives to gzip.

Note for specific domains, such as text, photographic images, scanned text, there are domain specific codecs which are more preferable.