newbie: multiple device ring

[nevoz]

Hello All,

I currently use MyNetFone as my VoIP provider (Australia). I have two SIP phones registered to one MyNetFone account (both phones using the same SIP credentials).
As it stands, the problem I'm having is that when anyone calls me only 1 of the phones will ring. If I disconnect one phone, then the other one will ring. What I'd like is to have both phones ring at the same time.
I've read somewhere that if I sign up to Voxalot, then I can get both phones to ring if someone dials me through MyNetFone. Could someone please:
(a) confirm that Voxalot will let me achieve this outcome, and
(b) let me know which Voxalot plan I need to sign up to.

Thank you!