Today I want to talk about the role of encryption.Scenarios for network discrimination typically involve an Internet Service Provider (ISP) who looks at users’ traffic and imposes delays or other performance penalties on certain types of traffic…. For example, if the ISP wants to penalize VoIP (Internet telephony) traffic, it must be able to distinguish VoIP packets from ordinary packets.One way for users to fight back is to encrypt their packets, on the theory that encrypted packets will all look like gibberish to the ISP, so the ISP won’t be able to tell one type of packet from another…. The ISP would see nothing but a bi-directional stream of packets, all encrypted, flowing between the user’s computer and the gateway.The most the user can hope for from a VPN is to force the ISP to handle all of the user’s packets in the same way…. The ISP can back down, by easing off on discrimination in order to keep the user happy – or the ISP can call the user’s bluff and hamper all or most of the user’s traffic.But the ISP may have a different and more effective strategy…. If the ISP imposes jitter on all of the user’s packets, the result will be a big problem for VoIP apps, but not much impact on other apps.So it turns out that even using a VPN, and encrypting everything in sight, isn’t necessarily enough to shield a user from network discrimination.