Could you be a little more specific i.e. in what context? where are you seeing it?
However a quick google gave this:
"NetWaiting is installed on Dell laptops with Win XP Pro. It provides a faciliaty to allow a user to suspend their internet (net) connection on the modem line while the user uses the line for a voice communication. At the end of the voice call, the net connections can be restored."
If that's what you mean?