Advance Option In Sip Device

Advance Sip device can only be used in PBX, admin first needs to add the MultiTenant PBX addon from enterprise.
After adding PBX it will reflect the addon in the customer account’s sip device
Advanced option is used to route the calls with the help of several features, known as Call Routing.

Menu Location : Customers→ Customers Edit→ Sip Devices.

There are several features that customers can use in the Advance option to route the calls along with the feature of allowing recordings and pickup groups, as shown in the below screenshot.
Customers can forward the calls to other extensions or PSTN.

Call forwarding- If the other sip device wants to forward the call to another sip device or another PSTN number, then the customer will enable the call forward.
On busy- Suppose the customer dials the number that is already on call but it can be routed to another extension or PSTN if the call is busy somewhere else.
No answer- If the other sip device will not answer the call and suppose the no answer field is enabled and forwarded to another extension or PSTN it will redirect the call there.
Not registered - In case the number we tried to call is not registered on the destination side and if this feature is enabled then the call will route to that extension or PSTN.

Import note : In ASTPP v6 customers can allow call recording for that account from the advance option also.

If customers are using the PBX feature pickup group then the configurations to allow the selected groups can also be defined in this field.

ASTPP Documentation