But how are you sure that the server isn't working?
Have you tried to connect to that server using your external IP (no the 192.168.#.# IP) from another computer?
Or you just want to host a LAN server?
Try to ping your own external IP from another computer using the following command in the command line of windows (to open it press Windows Key + R and the write cmd and then press enter):
ping YOUR IP:28960
example if your ip is 124.123.45.12 then write in the command line:
ping 124.123.45.12:28960
If you server is online, you should receive response.
Maybe try with and without the :28960, just in case.
To know which is your IP go to http://www.whatismyip.com/
Also, to discard problems, maybe it would be better to do all this without the router, I mean if you have a router and a modem connected to your router, connect the modem directly to the PC (you may have to create a new connection, maybe PPoE or another, depending how is configured your internet service), to reduce the number of possible variables that are impeding you to host the server.
Also another problem you perhaps have is something that happened to me when I used to host a LAN server on my computer.
I started hosting the LAN server but the first time I configure everything and have the console of the server running, from the other computers they couldn't connect to it...
And what was the solution? Without closing the server, open another instance of iw3mp.exe and host a new server... and the close the first one.
Doing that, I could connect from the other LAN-computers, I don't know why was that, but I solved doing that.
Finally, do you have your cod original? Because if it isn't, I think hosting a server doesn't work in the traditional way that does the original, you have to download a modified server file iw3mp... but of course, I can't provide you any link and also it's illegal.
I did some online searching, and got some information. It seems this problem is universal across all platforms. I still haven't found a definite cause for this problem, (though some are generally blaming crappy game/DRM design) or any statement from BioWare, but the community has come up with a few workarounds. I've had success with two, and haven't really bothered with the third. But there are some claims of the third being fairly reliable.
(Maybe console-specific, or PS3-only.) Disable auto sign-on to the console's multiplayer network (e.g.: PSN, Xbox Live) and reboot. Or, just log off of the network before starting the game every time. If multiplayer functionality is desired, use the in-game menu to sign in to EA's servers and this should automatically prompt you to sign into your console's network also. This has worked well for me. I suppose the PC analogue would be to turn off Wi-Fi or unplug the network cable.
Enable auto sign-on to EA's servers within the game. (You may have to try options 1 or 3 first, to get into the game menu needed to tweak this option.) This has also worked for me, and comes with the added benefit that you can re-enable your console's auto sign-on function as well.
Wait approximately 30 seconds at the "Press START button" screen. Some users have reported good results with this. Since options 1 and 2 are working fine for me, I haven't personally tested it.
Best Answer
Have you tried to start the game without being connected to the wifi and turn it back on when you are in career mode? That worked for me