Now that you have everything working the way you want it, you can now start receiving calls. Keep in mind that your cellular data will be used if you are using a smartphone app, and you get a SIP call while out. If you have accessible Wifi internet at home or work, then you should be able to use the Wifi network to make and receive calls. With that being said, be mindful of how many SIP calls you are receiving while not connected to a Wifi Network.
If you are using a SIP phone, then this shouldn’t be an issue unless you have a limited rate plan with your terrestrial ISP. If you are unsure, you would need to contact your ISP for assistance in this matter. The SIP phone will be a preference if you don’t want to receive calls when not home.