Can you still use your landline phone?

Your posting is very helpful.  Thank you very much.

I have a silly question:

Will it work if I still want to use landline phone?  Probably,  I need to use OBI 110 to set it up.

Right now, I am using iTalkBB. I would call relatives in China. But I am not happy with iTalkBB and looking for alternative to replace iTalkBB.

Any suggestion,  configuration details, etc are greatly appreciated.