Some of this stuff people will already know or maybe you will know everything posted here already, but for those who are having problems with connection, I hope I can help you in some way. There are various ways to open your nat type and maximize your connections potential online. If you struggle to join lobby's because your connection is on strict, or if you find yourself with an inconsistent connection (sometimes you will kill really quick and other times it's like..WHY DID HE NOT DIE?) than this thread should help you.
Starting with the basics!
Firstly, there are 3 Nat types and I'll explain which one will give you the best connection.
Nat types for setting up a connection
Nat type 1 (Best connection - OPEN )
For this type of connection, your modem is connected directly to the internet.
Nat type 2 (Good connection - Open/Moderate and sometimes/rarely might go strict)
For this type of connection, your modem is connected directly to your router.
Nat type 3 ( Bad connection, STRICT nat type)
You DO NOT want this kind of connection. This connection is a STRICT connection that limits your connectivity online.
Open nat type
This is the Nat type that you should always want to have because it means that your connection is not limited in any way.
Moderate nat type
While this connection is good, it's much more preferred that you have your nat type be open.
Strict nat type
This is the nat type that you do not want because it limits your connection online. You will find it very hard to join a multiplayer game with this kind of connection.
Setting up your connection to maximize your connections performance online
if you are connected online via a router, you may want to consider hooking just your modem so you can get a Nat type 1, connection. The reason for this is because, modems perform much better for a connection than routers. You will find that your connection is very consistent with just your modem hooked up, rather than your previous connection where you had a router setup. For those that have a very good connection, this will benefit you the most and I'll explain why. Most routers have something called, "buffer bloating". The better your connection is, the worst the Buffer bloating is. This is very bad for FPS games. Modems do not have any buffer bloating and this is why you will find that you kill people quickly & consistently, especially if you have a VERY good connection.
How can I setup my connection to get a OPEN nat type?
First, It's important that you know how you connect to the internet. Most people will just select "easy" to setup there connection or they will select "custom' but not choose the settings that are important. If you selected "easy" and also tried "custom" and have a moderate-strict nat type, than you chose the wrong settings, chances are, the reason you chose the wrong settings is because you may have a PPPOE type connection. If you have a PPPOE connection, than let's start there (That's the connection I have setup).
I"m pretty sure all DSL users have a PPPOE connection, so if you have DSL, but you are not getting an OPEN nat type, or you are trying to setup your connection to your modem but you are getting "strict" than follow these instructions.
PPPOE Connection - Wired
1. In the PSN MENU, go to network settings and setup a new connection.
2. select "custom"
3. select "Wired"
4. Operation Mode (Auto detect)
5. IP address setting (PPPOE)
6. type in your username and password of your PPPOE connection, if you don't remember it, find your paper/book that came with your internet and it will tell you the user/pass.
7. DNS (automatic)
8. MTU (I use automatic- but you might want to find out the exact MTU setting for your modem/router, if you want to use the exact MTU setting, otherwise just use automatic. I personally never had problems with automatic, so that's what I go with)
9. Proxy (do not use)
10. UpnP (enabled)
11. test connection
NOTE: If you can't get the best connection (wired) than you will instead need to select "wireless" and put in your wireless information. It's preferred that you "wire" your connection for a lag-free connection.
You should now 100% have an open nat type. If you are connected via a modem, you will get Nat type 1. If you are connected with a router, you will get nat type 2.
If you do not have a PPPOE connection, find out how you connect to the internet and setup your connection that way.
If you connect to the internet via a router, instead of a modem, and you still need help getting a Open nat type because you do not have a PPPOE connection, than you could try port forwarding your routers connection. You will need to get a static IP to port forward your connection and the full guide to port forwarding is below.
Port forwarding guide for ps3 - This guide is for routers only, modem connections will NOT need to do this.
Port forwarding guide Part 1: Setting up a static IP
All of this port forwarding information is from the portforward website.
FULL GUIDE, SEE LINK.
Turn on your PS3, and then navigate to the Settings option on the main menu.
Move down this list to Network Settings. Network Settings should be at the very bottom of the list.
After you have selected Network Setting, move to the right and select Settings and Connection Status List in the list that comes up.
Write down the IP Address, Subnet Mask, and Default Router displayed here. You will use same Subnet Mask, and Default Router down below. You will change the last octet of the IP Address and enter it below as well. More on how to do that later. Go ahead and go back to the Netowrk Settings menu.
After you have selected Network Setting, move to the right and select Internet Connection Settings in the list that comes up.
An short message will pop up. Press Ok to move on.
Select Custom for the setup method.
On the next page select Wired or Wireless connection depending upon how your PS3 is connected to your network.
We are going to setup this connection manually so we can forward ports to your PS3. So select Manual Settings.
Auto-Detect the speed and duplex settings.
We are going select Manual Settings on the IP Address Setting page.
Enter the the ip address you want to use for your PS3 into this page. It's important to choose an ip address that not in your router's dhcp range. You can check this by login in to your router and looking at it's dhcp or LAN page. Alternatively you can just pick an ip address that is not close to the ip address we found earlier. For instance if your PS3 was using something like 192.168.0.2, then you would want the new ip address to be something like 192.168.0.200. If your PS3 was using something like 192.168.0.240, then you would want the new ip address to be something like 192.168.0.2. Only the last group of numbers on the ip address should change, and that group of numbers would range from 2 to 254. Please, don't over think this just pick a number and go with it. I have just tried to provide some guidelines here so you can pick a better number.
Enter the Default Gatway and Subnet Mask we wrote down earlier.
You will also have to specify the DNS servers your PS3 will be using. This is usually required when your network's router is not passing the dns server information to the computers that have static ip address properly. First you need to find out what DNS servers your PS3 should be set to. The easiest way to do this is to give your ISP a call. They will probably ask you why you need them. Tell them the truth, your PS3 is requesting them. They should give you two ip addresses, one for the primary dns server and one for the secondary dns server.
Select Automatic for the MTU settings.
You should almost always select Do Not Use on the Proxy Server page. The only time you need to setup proxy server settings is when you connect through a proxy server. If you were doing that, you would have been given specific instructions from your isp on how to setup this section.
Set the UPNP options to Disable. UPNP should be turned off so it doesn't try to use it, instead of your port forwarding configuration.
Your PS3's IP Address should be Confirmed. If it is not then you have made an error in setting up the static ip address for your PS3.
Your PS3 should save your settings. Select the Test Connection option on this page.
All of the tests should pass, except the UPNP test. We previously disabled it. If you have already forwarded ports, you should come back with a NAT Type 2.
Port forwarding guide Part 2: Port forwarding the router
1. Go to http://portforward.com/english/routers/port_forwarding/routerindex.htm and select your router in the list of routers provided.
2. Now select the exact model of the router you have
3. scroll all the way down to "PS3 call of duty Ghost"
4. Follow the ps3 port forward guide you clicked on.
Final note of recommendation
Whatever you do, DO NOT DMZ your router. Some people will try to tell you this is the best way to open your nat type, but by doing this, you are bypassing the firewall and could damage your router. DMZ will indeed open your nat type, but you are at a great security risk, if you decide to go down that route. If you decide to go down that route because you are desperate to get an open nat type, than remember that there is a great security risk involved by doing so.