If I answer my phone and say more than that I am not working then its work. Ie if they still want to ask questions after I have informed them that I have left work and have the right to make me work (ie call center, boss or team) I will considere that work.

The way we are set up is that calls taking longer than 15 minutes (and that is how long I will make sure a call will take that I have to work are) will be counted as 3h work (unless on call and then only 2h). If we are scheduled as on call we have blank addition to our salaries, but need to be able to be at work in 90min. We get overtime and used to always aply to the union for extention of the max overtime roof, it got to the point that they sometime forgot to inform the worker that they had passed their overtime maximum. That was a time where all my collegues including myself destroyed our health by stress related issues, happily that has changed and overtime is no longer a problem. The change came due to us taking a stand forcingour bosses to order all overtime for a while and stop working on projects in the end of the day, the lead times that extended made the managment realise that we where not joking when we always asked for more people.