Calls droppping after 30 seconds

[Jensen_Yealink]

Hi Gnuijten,

regarding the issue, could you please share more on this:
1/ how often the calls was dropped? every time the issue happened, what prompt on LCD?
2/ How many ways call establish while the issue happened? Every time the issue happened only on the same handset or all five handsets may have the issue?
3/ while the handset drop the call, can other handset dial out another call normal?
4/ how about the LED indicator on Base while the handset drop the call.
5/ could you share the detail process to reproduce the issue, we will also try to testing on our Lab.
please kindly help with above, we will also involve our R&D guys look into the syslog you provided.