Multisite

hi guys! i got few questions about asterisk. i’m new to VoIP and of course asterisk. i’m planning to set-up a multisite using asterisk. my server is in the philippines and i’m going to place an ip phone in hong kong. the ip phone is behind the router with no NAT. my questions are:

  1. Do i need to have a public ip for my * server?
  2. Can i use private ip for my * server? if yes, can the ip phone with private ip add register to my * server?
  3. Do i need public ip add for my ip phone just to register in my server?

i just want a pure VoIP… thank you very much… :blush: