Communications are more advanced then ever. With the advent of the comm system, a ship pilot, for example, can broadcast a message across an inhabited system on an open frequency, or to a specific recipient, if they have the transponder frequency. Comm devices can be hand-held, built into helmets, ear pieces, and are installed on all ships. Personal devices usually have the range of whatever planet they are on.

Voice messages can be left for a specific person as well, and can be about ten minutes of speech.

Also, due to the unique frequency that one can have, they will never get unsolicited calls. its like an instant messenger, you have to add someone's frequency, then they add yours, and then you can talk to each other. So, simply put, having someone's frequency does not mean you can communicate with them.

Ship comms are encrypted for most military vessels as well, as are ones that wish to be kept private.