I have a customer on V15.5 and they have 1 SIP Trunk and 1 DID for their main line. On their old analog phone system with the main line and 3 rollover lines they would get their first call on line 1, second call on line 2 and so on. I am trying to configure this in 3CX so the receptionist that answers all calls can be on the first incoming call and when the secon call comes it would ring and then they can put call 1 on hold and answer line 2. I would like to label the line keys line 1, line 2, line 3 and line 4 since they have a 4 SC License. Is there a way to do this and how?