how the ISP can filter encrypted traffic ?

[mohammed hashim]

hi,

I do use VPN service which encrypt my traffic when it goes to the internet, through my ISP,

but my ISP can still be able to block some traffic, like I noticed video call voice of several applications are blocked,

I have tested more than one VPN application, same thing,

so how this work !?

[nspasov]

Hello Muhammed-

I have a couple of questions:

1. What type of VPN service/provider are you using?

2. Is your VPN service web based or client based?

3. Can you list some of the applications that are being blocked?

Thank you for rating helpful posts!

[mohammed hashim]

Not sure what is the type, the software I am using is F-Secure Freedome, and it is client based

I also tried Hexatech, but same result,

for example IMO, and Whatsapp, I can make video calls, but with no sound. but voice call works fine

without VPN started, I even cannot start the video call neither voice call,

[nspasov]

Hmm, the only way I can see this being possible is if your ISP is doing SSL Inspection/Decryption and intercepting your traffic. But that will be a good question for your ISP directly :)

Thank you for rating helpful posts!