You can call, transfer and forward calls to the group by dialing the calling group number 71 to 74 respectively. The simultaneous page function, accessed by dialing *70, pages the extension connected to a loudspeaker paging device and the users who are members of Calling Group 1.  

These groups are Ring All groups, that is a call to the group will alert all the available group members (those not already on a call) until the call is answered.

For Key mode systems, these groups are only used internally. For PBX mode systems, these groups can be selected as destinations for incoming calls within trunk settings.