NAT Type 1:
Your Playstation is the PPPOE dailer (through Ethernet NIC cable) where you enter and save your ISP's login and password in your Playstation, while your modem is configured as bridge mode while connected to your Playstation Ethernet NIC by cable (or direct cable connection).

In this mode your Playstation cable Ethernet network port will hold the public IP address.
So any ping, port scanning, brute force, DDOS attack from the Internet, your Playstation firmware OS will face all of it directly. (THERE IS NO FIREWALL HERE!)

However, in this NAT Type 1 mode any ports can be freely opened or closed by your Playstation, so you will not have failure to accept any incoming connection requests from the Internet by other people to any port numbers (to host chat server, host game server, and etc) unless your ISP sucks and blocks any uncommon port numbers.
If in this kind of PPPOE dailer you are unable to get NAT Type 1 when your Playstation is holding a public IP address, then this is ISP-side firewall blocking.
Reconnect PPPOE to get an unblocked public IP address or just change your ISP to a better one.

* And none of your LAN devices can connect to Internet since the public IP is hogged by your Playstation and it can't share the Internet with any other devices since there is no ICS setting (Internet Connection Sharing) like Windows.



NAT Type 2:
Your modem or your router will be the PPPOE dailer where your ISP's login and password is saved in either the modem or router.

The public IP address will be held by the modem/router.
Any ping, port scanning, brute force, DDOS attack from the Internet will be faced by the modem/router's firmware firewall.

Your Playstation will hold the LAN IP address on either the cable Ethernet NIC of WiFi interface.

Most people will get NAT Type 2 in this kind of network setup where the low end modem/router firewall do not have any restrictions on TCP/UDP outgoing requests and allows your Playstation console and (your PCs too) to freely connect to any service ports hosted on the Internet (ex. port 80 for HTTP webpages, port 443 for HTTPS, port 21 for FTP patch servers downloads, and etc.)
This can also be easily achieved by enabling uPNP support on both the modem/router and Playstation console together.
uPNP will auto open ports or delete port forwarding in modem/router firewall in real time, whenever you start or end the game or apps. (However, some uPNP support is buggy on some modem/routers!)



NAT Type 3 :
Same network setup like NAT Type 2 above BUT the firewall on your modem/router is too restrictive like a corporate Internet gateway that only allows very limited outgoing TCP/UDP requests.

Want to access "www.playstation.com" website/webpage? TCP HTTP port 80 ? OK!
Want to access "www.playstation.com" store secure website/webpage? TCP HTTPS port 443 ? OK!
Want to access "www.playstation.com" FTP patch server for downloads? FTP port 21 ? SCREW YOU, DENIED!
Want to access BF4 server to play online? TCP port 1935, 3478-3480? UDP port 3478-3479? MUST BE SOME KIND OF UNKNOWN ALIEN PORTS! SCREW YOU, DENIED!

This can be resolved to NAT Type 2 by either manually specifying every required TCP/UDP outgoing and incoming ports numbers in the modem/router firewall settings (Port Forwarding/Virtual Servers).

Shortcut :
Specify your Playstation LAN IP address as DMZ in your modem/router firewall where ALL incoming & outgoing ports will be handled by your Playstation.
(Not 100% solution due to DMZ implementation could be different depending on hardware and firmware of your modem/router. Sometimes it is just plain faulty and buggy)

Not so Shortcut :
Replace the modem/router to an easier home consumer grade where the firewall are more relaxed and easy.
Or be like a Boss and do a direct PPPOE dialing connection from your Playstation to get NAT Type 1 and face all the Internet attacks like a hero.

This post has been edited by Hattori: Nov 21 2014, 10:51 PM

Usually not possible.
ISP do not give public IP addresses to hotspots since wasting a precious public IP address on it will confirmed under utilized.