Nopac Etops
Descent procedures are spelled out in the Jepps regarding cabin pressurization failure on NOPAC routes. An offset left/right 25 NM to clear the airway, THEN descent to a lower altitude.
For those about to say 'one must descend right away', the answer is no. The procedure is takes into consideration passenger oxygen availability. In my case, 22 minutes on the 777 for the passengers. The lateral offset and descent will not use up the 22 minute availability.
Safe flying gang.