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The application requirement is to download files from FTP server,This is a very common requirement, are there any samples to match the requirement .
Please refer Background transfers documentation ,
Background downloader is ideal for uploading and downloading large files using HTTP(S). FTP is also supported, but only for downloads. For getting sample code, please check this Background transfer sample.
How many concurrent download requests can the application make for faster downloads.
There is no limit for concurrent download requests. and the download speed base on the network bandwidth. The larger the bandwidth, the faster the speed.
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