http://www.gstatic.com/generate_204
http://wifi.vivo.com.cn/generate_204
http://proof.ovh.net/files/100Mb.dat
http://speedtest.oktab.eu.org
http://www.apple.com/library/test/success.html
http://captive.apple.com
http://204.ustclug.org/
http://connect.rom.miui.com/generate_204
http://www.g.cn/generate_204
http://www.google-analytics.com
