keeping my ATA registered with FWD?

[isolve]

I saw the following about keeping my ATA registered with another VSP in the tutorial.

"There are a number of reasons you would want to keep your ATA registered with another VSP.

1. If your VSP requires you to have your ATA registered to be able to make outbound calls, then you will need to register you ATA to that provider (or find another provider).
2. If your VSP provides you with a DID, you will probably want to register your ATA to that provider to allow incoming calls to ring your ATA.
3. Some VSPs don't allow inbound SIP URI calls and also require you to have your ATA registered to them to make outbound calls. If this is the case the only option you have for receiving inbound SIP URI calls that will ring your ATA is to use inbound IP dialling (or change VSP)."

I have FWD. My friend would call me using FWD software. PSTN user would call me by calling my IPKall number.

Do I need to keep FWD registered on my ATA? Can I still receive call if I only register Voxalot on my ATA and add FWD in my Voxalot account?

Thanks.