>>86490>>86475They specified that the time window is 15 minutes. You can check your logs to see if they're right.
https://social.technet.microsoft.com/Forums/lync/en-US/3ccbdab0-68f0-46ed-b0d0-ca003e35c440/ip-address-change-eventlog-in-windows-system?forum=winservergenAnd if so, you can call your ISP demanding an explanation if it keeps happening. Even if it's your modem, that's their equipment failing. It's not an unreasonable demand, either. Lots of online services demand at least moderate stability.