Many time per day, the 4 green lines of mine SPA504G desk phone would turn orange. During this time, if there were any calling ongoing, the call will still going as normal; however, there is no new can be be established.
Ping to the IP of the phone will still receive reply.
The issue would take about 10 seconds to resolve itself.
This issue just started to happen about 5-6 days ago.
The firmware on the phone is 7.5.6a.
The phone is registered to a FreePBX server version 10.13.66-22 running on the same internal network. The current Asterisk version is 13.18.0.
I upgrade my FreePBX server to these version during the 2nd week of Nov. 2017.
Is there any one having any clue about what is going on?