How Is IP Call System?

Hi,

I dont really understand your question fully. But here is my answer to what I believe is your question.
A good example for an IP Call system is Vonage another name for this is VOIP which stands for Voice Over Internet Protocol. To use an IP Call system/VOIP you do need to have a current Broadband internet connection like DSL or Cable.
A friend of mine has a VOIP service at his home and it works great, in my opinion there is hardly no difference between a normal telephone and a VOIP.

Here is more info. of Vonage if you would like.
http://vonage.com/index.php?ic=1&SERV=test1