Hello i want to develop the chat/call application like viber,whatsapp etc in Android using sip. i am bit new. i want to know how i can register the sip account.suppose if i want to chat or call between other person how i can get register without telling user that i am going for sip registration. where i can save user message and how i can maintain user info like dispaly name , display pic etc.is there any serverside databse involvement to save messages,pic etc or sip sever maintain automatically.
A server would definitely be involved. Either GlassFish with SailFin or Mobicents might do the trick. Going by my own previouus attempts to find out what's possible I'd guess that you will not find much available material or help online, and need to piece most of it together yourself.
If you're new to Android then this is way too complicated a project to tackle. You might want to restrict yourself to a chat app (for which you'd also need a server, but that's easier to set up, assuming that you have server-side development experience).