If you’ve thought that the VPN on your iPhone hasn’t been working properly in China lately, it’s not just your imagination. Virtual private network provider Astrill said on Wednesday that iOS devices that use VPN protocols IPSec, L2TP/IPSec and PPTP are not accessible in China right now. So far, it’s just iOS devices like iPhones and iPads that are affected. Astrill VPNs on MacBooks still work.

VPN Tech Runo said earlier that many of its services have not been accessible in China either, since December 31. 

An unidentified website that monitors the Chinese internet explained what’s going on:

The Great Firewall is blocking the VPN on the protocol level. It means that the firewall does not need to identify each VPN provider and block its IP addresses. Rather, it can spot VPN traffic during transit and block it.

With the Great Firewall getting harder to climb, companies like Astrill are charging more to do it. The popular VPN provider has already raised its prices to coincide with the Great Firewall update.

Keep in mind, though: there are a number of great VPNs out there. Let us know of others that might work better in the comments.

Photo: flickr