We have an SMC high speed router and use time warner cable as our ISP. The DHCP provides a different IP address for each computer or device which there are 4 or 5. Anyway, my brother and myself are trying to go into the same room but when we do one of us goes 999 ping to everyone and vice versa. It will work for a bit and then go back to 999. I tried port forwarding, which I'm not exactly sure how to do. I went into the SMC router, went to firewall, then to virtual server and created a port forwarding, first I initially did it with the general ip address on the back of the router and used port 7900-8000 when that didn't work I tried using the DHCP IP address for the pc I'm using. I also tried 8000-8100 port settings. When I do this I also changed the port numbers in the gunz game through options.

Here's what it looks like when I try to port forward:
Virtual Server Settings
IP Address 192.XXX.X.X
Private Port 7900
Public Port 8000
Protocol TCP & UDP
Comment Gunz
(The maximum rule count is 32.)

I appreciate anyone's insight and help. Thank you.

ijjiLizard said he had a similar problem in the past. They somewhat solved it by having one pc using wireless and the other through the ethernet cable. Then he asked if I had a USB modem cable and I found one but I plugged it in while the pc was still on disconnecting the cable from the router. Once I got the usb modem cable directly into the modem to pc the pc said it didn't install properly. so, i'm going to restart everything, modem with usb cable in, router and pc. I Hope this works.

I got it to work part of the time, sometimes it works fine for awhile and other times it doesn't. By rejoining the room seems to help. Here's what I did, I port forwarded one computer to 7700-7700 and used one IP address and then the other computer I port forwarded to 7701-7701 and used a different IP address.

Nice, glad to see you got somewhat of a solution to work. This reminds me of when my bro used to play and we would always have 100 ping to each other(in the same house lol...). See you in game!

Here's how I port-forwarded Gunz:

1. Press and hold the windows key + r on your keyboard to open the run window
   
   
2. Type cmd.exe, and press enter
   
   
3. Type ipconfig, and press enter once again
   
   
4. Look for your default gateway and copy that address in your browser
   Most of the time it's a 192.168.X.X format address
   
   
5. A dialog box will pop up asking you for a username and password, try the defaults: admin: admin, admin: root, root: admin, admin: blank, and if these don't work you could try a website that shows the defaults for each brand, e.g., http://www.routerpasswords.com
   
   
6. At this point if you still do not succeed, you can try resetting your router manually and typing the default username and password again
   Here is a good reference for a step-by-step explanation: http://www.tp-link.com/en/article/?articleid=109
   
   
7. Once you log in successfully, find your port-forwarding section
   
   
8. Add a rule for the port range 7700~7800, and select the UDP protocol
   I don't think TCP would be required because it is a very fast-paced shooting game, and I would be very surprised if they used TCP for anything; but, you can add a rule for it if you feel as if it would make a difference
   
   
9. Close your browser and enjoy!
   

P.s. Malamutewolf, I believe your port range could have been incorrect.