Connect to PS3 Game On Line

First check you've forwarded the ports correctly
Compare with this process:
http://www.portforward.com/english/routers/port_forwarding/Belkin/F5D8635au4A/PS3_Call_of_Duty_-_Modern_Warfare_2.htm

Check your Windows firewall is allowing all the ports to be open and any third party security software is also set to allow this.
 
Are you using a wired connection between router and PS3?
Is the PS3 connecting to other servers OK?

I have used the link that you sent me before. It is the same one that Sony advised me to use and I am sure that I have done it correctly. Why do I need to check Windows firewall? The PS3 is connected directly by wire to the router. I am able to play Little Big Planet on line but this does not require ports to be opened.

Had this happen on my PS3 and had to manually set the DNS servers. My ISP's DNS wouldnt work for this for some reason so i just used these:

208.67.222.222
                         208.67.220.220

You may need to manually set the IP as well to a local IP. Im not sure what Belkin uses for their IP's but it should be something like 192.168.1.XXX where you want to change XXX to an unused IP on the network.

Is your firmware version 1.07?

Windows firewall was my mistake - I meant Belkin firewall
See p.49 onward here:
http://cache-www.belkin.com/support/dl/pm00781ea-usermanual_uk.pdf

What is your uPNP setting (on/off)?

Thanks Masqueraid. My Router has firmware version 1.00.23 and the update check tells me that this is the most up-to-date version.  UPnP is enabled. I have tried that connection wit the Router Firewall disabled and still can not connect to the ports! At the moment I do not know if this is a Router, IPS or PS3 problem.

If you go into the multiplayer screen on MW2, it will show you information about your connection. Look for NAT Type. Do you see NAT Type 1, 2, or 3? Below that, do you see Strict, Moderate, or Open?

Here is a good guide posted on Infinity Ward's forums:

http://www.modernwarfare2.com/forum/viewtopic.php?f=28&t=231094&sid=81968fb7c482282380f8de660c356248

As HamStab mentioned..
I had a similar issue and it seems to come back to a NAT issue..
Regardless I also manually set my PS3 with its own static IP address and DNS and so on..

To do this you will need to first find out what IP range your DHCP is set up with..
To do this on a windows machine press START/Windows button and go to run or click in search and type CMD
This will open a black and white text screen..
In this screen type IPCONFIG and note the computer IP Address and write it down..
Also note the Gateway address as this will be the address for your router..
Assuming it is something like 192.168.1.### I will show you the settings I used on my PS3..
NOTE: The IP range may not be the same as I mentioned above it could be 10.0.0.### or 192.168.0.### or something else.. so if your DHCP range is 10.0.1.### then the PS3 IP mentionedbelow should be 10.0.1.250

The manual IP Settings I used are:
PS3 IP = 192.168.1.250
PS3 Gateway = 192.168.1.254
PS3 DNS 1 = 208.67.222.222 (OpenDNS)
PS3 DNS 2 = 208.67.220.220 (OpenDNS)

Router
Router IP = 192.168.1.254

Now set up a DMZ to your PS3 IP Address and this will basically publish it directly to the internet and it should work..

I do not have my PS3 DMZ'd I went through with some port forwarding and have had no issues with the following games:
Little big planet
BF1943
War Hawk
MAG (beta)

Before I set my PS3 up with manual IP settings I had issues with it even communicating properly with the PSN.

Regardless,
Good luck!

Thanks for all the suggestions. I tried most of them - I do not have another router - but am still not able to connect to the game on line. Waiting for matchmaking server message is displayed with NAT Type as .. in the Call Of Duty MW2 program. Why is my setup so unique? Belkin Router wired directly to a PS3 !

You see dots in the NAT Type displayed?

Yes on the MW2 multi-player screen. The PS3 connection test is successfully though and shows NAT Type 2.

What IP do you get on your PS3?
What IP does your Belkin(gateway) have?
Just to confirm, you can navigate to webpages on your PS3 when connected to the Belkin, right??  
Another thing you might want to try is hooking the PS3 directly to the Internet Provider's Modem just to make sure the game works fine without the Belkin router.  Let me know if this works

Let me know the answers to those questions. We will go from there.

My PS3 get IP 192.168.2.30 and the Belkin gateway is 192.168.2.1 and yes I can navigate websites on the PS3. I do not have a separate modem.

So was the Belkin router given to you by the provider? If not then you should have a box that was given to you by the provider that plugs into the WAN/Internet port on your Belkin router.   Take that cable and plug it directly into your PS3 and restart the PS3 and make sure the PS3 gets a new IP. Then try and play the game.

Also if you don't mind me asking who is your provider?

In a pefect world Ordi's idea should work and open that router to allow all traffic to that PS3, but really you shouldn't need to do that at all.  The settings for your specific static setup are below.  Then go into the Belkin router and put 192.168.2.30 into the DMZ
PS3 IP = 192.168.2.30
PS3 Gateway = 192.168.2.1
PS3 DNS 1 = 208.67.222.222 (OpenDNS)
PS3 DNS 2 = 208.67.220.220 (OpenDNS)

If at all possible I would really try to take that Belkin router out of the picture as a test.  If the provider provided the router possibly ask for a replacement.

My ISP is Plusnet and they only provide a modem with the package if requested at an additional cost. I have exactly the setting that you describe above. Thanks for confirming this. I agree that replacing the router in the network will either confirm or eliminate this as a cause. It is still under warranty and so I will take it back and get different one.

Thanks again

Wait!  Before you run to replace the router can you plug the cable from your modem directly into your ps3 and see if you can or cannot play the game.

If you still can't play the game then we know its not the Belkin Router and no need to warranty the Belkin.

Remember if you have static routing on your PS3 then you will have to erase all that and have it dynamically grab an IP from the modem.. You may need to power cycle modem follow the below steps to power cycle correctly:

Set PS3 to dynamically grab. If it grabs an IP from the modem then  no need to power cycle.
If an IP isn't grabbed try restarting your PS3.
Still no IP? Then power down PS3 and then unplug modem for 2 min, then plug it back and wait for all connection lights to come back on the Modem. Then once modem is fully booted turn the PS3 back on and you should get an IP.

Once you get an IP from the provider then try and play the game.

Let us know the outcome.

The Router and Modem are combined in one Belkin unit and I only have on end of them!

I see. Then your provider should be able to help you configure the Belkin correctly.  They may even have a frimware upgrade available. Have you called them yet?

With all the above set reset the router fully(power off)
Maybe reset the PS3's network settings again..
You could even go out on a limb and maybe consider factory defaulting your router and reconfiguring it again to be sure everything is set right and there are no issues with the software on the router..

Failing that my actions would be to get your hands on another router, preferably another brand.. say a friends or another family members or even just but another and see if that works..
I am using a Billion, but you could also try a Netgear or other decent brand of router..

:/

Best of luck!

Thanks for the comments but nothing new. I have contacted the router supplier (Belkin) 3 times before now and carried out both soft and hard resets but without and success. Off to buy a new Router tomorrow and then we will see.

I've a belkin on my PS3 and I used to have some issues with PSN disconnects and DNS.

I found flipping between wired and wireless fixed it on the day it occured, and it stopped after a PS3 update and putting the PS3 in the DMZ.

Another thing to try if you are still having problems with a new router is when in MW2 and in Multiplayer, press the PS button and press triangle on Account Management to log out, and back in to the PSN. Then try again.  This fixed an early bug with joining friends online in MW2 so may help here.

Good luck!

Thanks all for trying but I still have no solution after trying a D-Link Router and all of your suggestions. Could my Microfilter be broken even though I get internet access? After that the only thing left is to change my service provider!

I replace my Belkin Router for a Netgear one and that worked. I did not need to DMZ or Open Ports it just connected straight away!