I want to build security surveillance system for my office.
What i want is using 3 or 4 IP cameras/Network Cameras such as Axis 206 or D-Link DCS-900, 1 computers as a viewer only and 1 computer as a viewer and recorder (i separate the place of the 2 computer)
I don't have internet connection.
The problem is, what kind of device that i have to use to connect those cameras together and view them in one window in the same time by using a software? is it a hub, switch, or a router ?
A hub or switch will both work as far as the physical connecting of everything together. For the software, you'll need to make sure that the IP cameras support what you want to do. Most of the cameras I've seen just have a built in website that you go to in order to see a live feed. I don't think that type of camera would support recording the feed to disc.
If you don't already have a network in place, it will probably be simpler and cheaper to just buy a normal, non-IP, camera system.