Feature Manual References
9.1.4 ICD Group Features—Outside Destinations
19.1.2 Virtual PS
13.1.17 Private Network Features—PS Roaming by Network ICDGroup
Description
One PS can be registered to up to 4 PBXs in a private network, and a Network ICD group created for the PS
at each PBX, with virtual PSs set to forward to the other PBXs in the network. When a call to the PS is received
at one of the PBXs, the call rings simultaneously at all PBXs in the network to which that PS is registered.

PBX-1

Private network

PBX-2

Telephone Company

Virtual PS3

Virtual PS2

Virtual PS1

PBX-3

PBX-4

ICD Group

Each virtual PS is set to forward calls to the extension number of the actual PS as registered at one of the
other PBXs.
Then, an Incoming Call Distribution (ICD) Group is created containing the registered PS and the virtual PSs.
When a call is received at one of the PBXs, it is forwarded to all of the other PBXs. One private network channel
is used to forward an incoming call to one other PBX. Therefore, if a PS is registered at 3 other PBXs, 3 private
network channels are needed to forward a single call to all of the PBXs.
Each PBX can store the current communication status of each PS (In Range or Out of Range). If the status of
the PS is set to Out of Range when a call is received, the call will be refused and the private network channel
will be released immediately. Since the PS can only be set to In Range at a single PBX at one time, any other
PBXs to which the call is transferred will refuse the call, releasing the VoIP or ISDN channels.
Conditions
•Hardware Requirement
252 Feature Manual Document Version 2008-11
13.1.17 Private Network Features—PS Roaming by Network ICD Group