The transmission data is very precise. It contains no content on transmissions. It does not reveal substance, the meaning, or the purpose of the communication. It more or less identifies a type direction data—the date, duration, and so forth. So it's actually similar to phone call data today. If I were to make a phone call I know that this number called that number. So it' the same thing with this computer calling that computer. So we're establishing the link.
