134 Special functions for parallel call (ONS)Special functions for parallel call(ONS)If your telephone is integrated into an ONS group (ONS = "One Number Ser-vice"), you can be connected to all other telephones of this group in the sameway as on your own telephone. To set up an ONS group, contact your respon-sible administrator.One ONS group may consist of max. 3 phones (phone numbers).Max. one group member may be an external telephone (e.g. a cell phone). Onephone in the group is the "master" (A), whose number also given to the othermembers (B, C) of the ONS group.If A, B or C are called then all the phones in the ONS group will ring. If A, B, orC is busy, all phones in the ONS group are busy (busy tone for a caller from out-side the ONS group). Within the ONS group, the phones can be reached withtheir original call numbers.Further effects on the phones of internal participants of an ONS group are alsoavailable with the following features:• Call waiting page 82• Call forwarding page 73• Do not disturb page 136• Mailbox (MWI) page 109• Callback page 76• Conversations page 27If your ONS group contains a cell phone, make sure that it is always avai-lable (switched on). Otherwise it can lead to problems with the call signa-ling for other ONS group participants due to the premature call acceptan-ce by the mobile mailbox.A (Master) B CONS Group
