I have a problem with making a conference call on Cisco 7936 station.
The station is registered on UC520 running 12.4 IOS, as regular IP
phone(ephone-dn 15, number 114).
Calls from this station and to this station are working ok, as are call
transfers and company directory usage.
Upon establishing an active call, when the Conference soft key is pressed,
the station displays text: NO LINE AVAILABLE.
In the attachment, there is a sample of running configuration.
I have this problem too.