Panasonic KX-UT133 and Asterisk 11 - how to force a second call to be accepted (call-waiting, etc.)?

Question

Asterisk

Asterisk 11 on CentOS6, no add-ons, several models of SIP phones,
call-waiting enabled, call-limit>1 (2,3,10 - depending on the model) on all, registered
as a friend, the second call is normally accepted for all, hold call; even BLF works...
For Panasonic KX-UT133 model - when a subscriber is talking, an attempt to dial him causes
the answer "486 busy here" from the IP phone (not the server) and short beeps, as well as an attempt to
forward an incoming call to him. For the sake of interest, I registered a second line
on the same server under a different name - when the first line is busy, an attempt to call
the second one also gives out "486 busy here".
Where to dig? Native tech support said: "solved in one line on the server",
but which one - they are silent, like partisans.

Answer 1

Yeah... in the new Panasonic KX-UT1xx firmware, call-waiting was disabled, and this parameter is not controlled from the web-face. It is solved by the auto-provisioning setting and the config file, it is described in detail on the home site .

Answer 2

So is call waiting on the device enabled?