FYI,
After some tests found, that function "*is_audio_on_hold()*" (textops)
*supports
only rfc 254*3,
where "hold" is indicated by setting the "c" destination addresses
for
the media streams to zero (0.0.0.0).
The newest *rfc3264*, where "hold" is indicated by a=sendonly/inactive, *is
not supported*.
Kamailio version 4.4.6.
Best regards,
Julia