A few months ago, I moved teams within my company. I need to keep supporting some things I created for the old team, with no definite end date. That team has an expectation that anyone on the team can ask you to get on an audio (+screenshare) call at any time, and that they don't need to provide context - e.g., "got a minute?" or "jump on a call?". They're typically 5-15 minutes, but could be hour+ conference calls.
These calls took up a lot of time. I've asked explicitly (and encouraged implicitly) that if they have questions, can they send me/instant me/ask me the questions ahead of time, and give me time to work on them offline. I've written this in documentation, emails, meeting invites, instant messages, and said it during calls. It gets either ignored or shot down - e.g., "I'd rather do a call"; "it's too much work to explain"; "it has to be now".
Is it reasonable for me to expect that calls and meetings have some context, and that I don't want to drop what I'm doing at any moment for a 40 minute impromptu conference call?
Even if it is reasonable, it's not happening. Should I give up?
If there were a definite end date for my supporting the old team, it would help but not eliminate these requests, because they ask me to get on calls for projects unrelated to what I'm supporting. There's an expectation from my manager that this isn't permanent, but there hasn't been any talk (or action) about hiring or training someone to take over the work.