I love the way my team does it.

- All support tickets go into a Kanban board separate from the scrum board

- Whomever is primary oncall works exclusively in this queue and is excluded from the sprint for that week. Depending on volume, you can add a second goalie.

- If the support queue is empty, the oncall works on lower priority debt or other OE.

- Oncall changes weekly for us on Monday

As a manager, I love it because it's predictable for planning. The team loves it because they're not constantly jerked around.