Reply #4: It's the routing information at the start of each slug of data... [View All]

[HereSince1628]

From this you figure out who is talking to whom.

When you put together all the whos that are talking to whom you can construct networks of interacting individuals/telephones/emails.

In unsophisticated networks (sophisticated nets operate near maximum 24/7 using fake data just to keep the net busy)), the number of calls can be used to develop activity patterns (chatter). Changes in the activity pattern can be informational.