Phones - Why are my Digium phones slow to respond or randomly reboot?
If you're having issues with your Digium SIP phones intermittently becoming slow to respond, delayed key presses or randomly rebooting these issues could be due to a IPv6 multicast flood of packets coming from your workstations during a sleep state.
Intel has identified an issue in their i217-LM chipset that will cause workstations that are sleeping to send a massive amounts of IPv6 multicast packets to Digium phones causing them to reboot and become very slow or sluggish.
These IPv6 multicast packets can also cause other problems in your local area network as well and cause a degradation of service in the overall performance of your Switchvox PBX
To fix this issue, you can do the following:
Turn off IPv6 on the workstation(s)
Turn off Sleeping state on the workstation(s).
Source: https://communities.intel.com/thread/48051?start=0&tstart=0