When the PBX Center is called directly (using the pbx name or the 200 Alias), it starts the Auto-Attendant application.
Other PBX Center functions can be invoked by accessing the PBX Center via alternative names. By default, the CommuniGate Pro Router directs all calls to 7nn names to the pbx Account (where nn is a 2-digit number).
When the PBX Center application starts, it checks the address used to call it. If this address (the "local part" of it, the part before the domain name) is a 3-, 4-, or 5-digit number, the application uses the last 2 digits as the requested function number. The documentation below assumes that your Domain uses the 7nn@domainName address to invoke the PBX Center function number nn.
The PBX Center application requires authentication for most calls coming from its own Domain. You may need some exceptions from this rule. For example, your in-house gateway may send incoming calls to your PBX Center using the From:sip:email@example.com address. To accept these request without authentication, create the ExternalGateways Group in your Domain and include the gate1 name there. The firstname.lastname@example.org must be routable: for example, you may want to create a gate1 Account, or, more likely a gate1 Alias for one of your existing Accounts. If a request is not authenticated, the PBX Center processes it as an "external call".