Confirmed, are you sure you are not confusing ETP's with ETOPS? Equal Time Points (ETP) are points where the time to divert to one alternate is the same as to another. At those points you are furthest from an alternate, at all other points you will be nearer. The ETP where the diversion fuel required compared with the fuel on board is most critical, becomes the Critical Point for the ETOPS portion of the trip.
All parts of the ETOPS portion of the trip must lie within the still air distance calculated from the ETOPS approval time (say 180 min) at an agreed speed (approx 400 to 425), depending on your approval.
