I have a Cisco 7920 connected to CCME 4.1 running on a 2811 IOS 12.4(11)XJ via a Cisco Aironet 1100. The phone is running firmware 4.0-02-00. It is registering correctly to call manager express and I can make and receive calls.
The problem is that when someone calls this phone and hangs up before the call is answered, the incoming call is like locked on the 7920 and on the screen I have External Call(Unkno..
If after this, I try to make a call from the 7920, a "Line is Busy" message is displayed, however I can still receive calls on this phone.
Any help on this problem please?