A quick Google search of that error code will give you a few things to try:
First thing to try (I always do this no matter what problem I'm facing, even if the toaster isn't working properly.) is to reboot your router. If that doesn't help, it may be down to your routers firewall. It might not like the look of the outgoing/ingoing connections that your PS3 is making, or trying to make, therefore it may be blocking them.
Last simple thing is to check the strength of your connection. (if you're on WiFi) If you have a very weak connection to your router, it's more than likely that your PS3 keeps losing connection to PSN, even if only for a millisecond, hence you being booted from the PlayStation Network.
If none of the above things help, either pop back to this thread or message me on Skype. I'd be glad to try and help you out.