In Eurocontrol IFR, or inside any CAS, one way to wake up the controller is to do a position report, or ask for a radio check 
On a comms failure, I would do a DCT to the next WP on the filed route.
OCAS, just do what you like….
I think this (com failure when on the way to a waypoint not on the filed route) is one of the not 100% regulated bits in aviation. As you suggest, when approaching the waypoint, just wake ATC up by asking for some (convenient for you) DCT. I would not wait until I am past it and then just proceed to some waypoint on your filed route that seems to make sense. This will occasionally confuse ATC and cause a reaction (I know, it was originally the controller’s mistake not to give you an onward instruction, but as said above, there are more elegant ways to solve this.
, I would do a DCT to the next WP on the filed route.
But if you are off the cleared route, then which is the “next wp on the filed route”? The one 90 degrees off your present track? 30 degrees off? FIR boundary? AFAIK, this is not defined anywhere.
Yes, the whole business of a comms failure (which 99% of the time will be due to you having been forgotten about and then maybe flying out of the controller’s range) is not clearly addressed.
The really nasty aspect of it is today’s extremely nervous aviation security environment where anybody going out of contact for more than a short time is going to trigger all kinds of actions which no ATCO will discuss openly.
I don’t know the “rules of engagement” with light GA but an airliner doing it is going to trigger an intercept within maybe 10 minutes.
I don’t think anybody can pretend that setting 7600 and flying the filed route (with any national variation e.g. holding the last vector for 7 more mins) is a good idea – even if it was in your IR exam
What I have on almost every IFR flight is that the controllers are slow to issue a descent clearance. So i always “wake them up” with “request descent”, “ready for descent” or “standing by for descent” … but many times I have to descend with 900 or 1000 fpm to arrive at the IAF in the right altitude …
How do you handle that?
Getting point off route happened to me last week when flying back from Aero but it came as good ATC proposal: “I can give you good shorcut off your route if you can climb FL170.” Gladly accepted and saved another 5 min plus direct tailwind
So i always “wake them up” with “request descent”, “ready for descent” or “standing by for descent” … but many times I have to descend with 900 or 1000 fpm to arrive at the IAF in the right altitude …
I do the same thing you do. And it usually works except in busy airspace around groups of major airports, like LFP* where they have constraints that prevent them from humouring you.
Edit: actually I wake them up something like 5 minutes before the expected TOD
What I have on almost every IFR flight is that the controllers are slow to issue a descent clearance.
The software they use calculates descents with a rate around 1500ft/min which is what airliners like best. The best thing to wake them up is to request descent when it is convenient for you adding “not pressurised”. Many controllers are PPL holders themselves (two decades ago that used to be a prerequisite for becoming a controller) and will understand.
I’ll do just that the next time. Actually 1500 fpm is okay, if it’s not bumpy and without passengers …
I always try to do a continuous descent with -500fpm and about 50% power set.
It is comfortable and you’ll gain some speed back.
The GN430 vertical navigation function is very useful:
I use VNAV too – but I rarely pull the power in the descent. I enjoy those 220 KTAS descents :-)
