If you are receiving the 1800 calls via PSTN, you do ot need to do anything. The calls will be routed to your normal phone numbers, the ones connected already to the PSTN ports.
If you are trying to get the 1800 calls via VOIP, there are several troubles:
1)The Quintum could not play IVR over VOIP, then you will not be able to play the IVR to those 1800 callers.
2)All calls received VOIP could only go out of the box via the PSTN ports or the PBX ports.You will not be able to receive calls via VOIP and send them out via VOIP again, that is called a call relay box (start price around $6000 US dollars)
If you have not entered any I.P. on the “allowed” table, the gateway is open, anyone that have your I.P. could send calls.
If you enter even a single I.P. on the “allowed” or “barred” table, every gateway that will sedn calls need to be incluided on the list.
Here is a example of a “open” gateway.
Endpoint Authorization Type = 0 (None)
No Allowed Endpoints Configured
No Barred Endpoints Configured