how are they looking inside the packet if it's encrypted?
DPI doesn't have to decrypt it to make certain guesses about its content. For example, timing information, packet sizes, routing info, etc could lead you to believe it's certain kinds of things (SSH, VPN, etc).
alt Hacker News
DPI doesn't have to decrypt it to make certain guesses about its content. For example, timing information, packet sizes, routing info, etc could lead you to believe it's certain kinds of things (SSH, VPN, etc).