Call drops after X minutes

Hi all,
I’ve been getting some complaints from the team that calls get dropped after being on the conf call for at least 30 minutes.
They can’t pinpoint to exactly how long each call is but most of them “at least after 30 or 45 minutes on the call” and then dropped. Are there any parameters / settings that defines the max length of a call?
Thank you.

do you have a sonicwall router?