when online playing,the UISD will encrypt the play address:
http://uisdcntest2.versalsoft.com/ULinkSpy/UISDTestDir/1.mp3?urlid=mjvbhqedxjzhgephbd8p2hjemflwmenhpfm8pcbqfgqnlkjmtath
The encrypted string is related with client IP address informaiton so the encrypted string is different while the different IP users access this resource.( if you copy the address to other user who the ip address is different from you, he can not open the play file,and the UISD will think it is a illegal link)
Anti-downloading test:
if the music have been configed anti-download, it will only can online play and can not be downloaded. so click the following download address, The uisd will prompt the file can not be found.