Sorry, dude, but it is not.
Well, hum, I have been flying all over the world, including Africa, for 40 years. Except Brazil.
In every country and Air Traffic Control Systems I have flown in the first call when entering a new sector, new area, crossing any and all boundaries is;
1. Who you are.
2. Where you are. (If not in radar contact.)
3. What level you are. (Or what level you are transiting to and from.)
If there is no response from ATC you stay at the last assigned altitude (level) you were last assigned.
Now, just where is this not the procedure?
Inquiring minds desire to know.