Can a Switch transmit Modem's signal

Hi All,
I am willing to setup a network over a Satellite modem (only high speed available in the area) with a wireless router and DVR (Digital Video Recorder) that is connected to security cameras.
To view the cameras remotely over the internet via DVR we have a static IP. I am trying to figure out how to have both the router and DVR connected to the modem at the same time.

Following the rules it will be to first connect the modem to the router then the DVR to router. But I think it would require opening a port in the router, something I do not know how to do.

Someone suggested was to use a switch, with the set up as follows:
Connect modem into the switch and then connect the router and DVR into the switch.

Since i don't have any idea about it i would like to know from you all first then try to apply it.
Can a switch come before a router also, can a switch transmit the modem's signal?

Generally you need Switches whenever there not enough plugs on the routers.

Opening a port in the router is not that tough. follow the steps as told:

• Plug everything in, then type in the IP of the router into a web browser.
• You can find the IP from the router's owner manual.
• From there you'll need a password from the owner manual to get into the router settings.
• Once you log in, go to "Virtual Server" or something similar that will allow you to open ports and point them to the IP of your DVR.

I do agree with what Snake08 is saying. We have a LAN at our office, which at the start consisted of four computers, plus a printer. The router I use only has four ports on it, in addition to the WAN port. So I had to purchase an eight-port switch.

Later I had to connect the cable modem to the WAN port on the router, and then I used a cable to connect the switch to the router.

Instead of plugging three of the devices to the router and final two into switch, I plugged all of my five devices in the switch.

Opening the port through the router is quite easy try it you can easily do it.

Thanks Shen and Snake for your valuable time, i will surely try to open the ports in the the router.

cheers