The Chinese authorities have stepped up their internet security and have "upgraded" the Great Firewall to block some external internet traffic via VPN.
You may have noticed that the VPN works sporatically. This is because VPN providers use different protocols such as SSL/Open VPN, PPTP and IPSec, use different ports such as UDP and TCP 1194 and many diffferent servers all with multiple IP addresses. We have over 150 servers. All of this adds up to a "cat and mouse game" and frustratingly for you an an inconsistent service.
You have three options today a) Try IPSec on you iPad/ Android as it has been reported that the mobile service is much more reliable b) Use multiple providers and hope that one of them is working now c) Wait for the current situation to relax, which we hope will happen eventually as VPN is used is extensively for business and the blocking inhibits business activity.
We will be adding an additonal optional TCP port to offer a higher liklihood of a successful connection but unfortunately none of the solutions are 100% reliable.