Thanks for your responses. I'm not very familiar with the DCS system and am trying to understand the terminology.
We have set up an Operator group as Station Group 505. Those phones ring for all calls to our main number.
Each phone is linked to a DID number. All phones have a GPIK01 key. On those phones, the key flashes when a call comes to any other phone, but the phone does not ring.
We have four incoming lines (trunks 703, 704, 705, 706) which form one call group (call group 0).
Does this make sense?
Thanks, again for your help.