sometimes when you disconnect from the blackbox on cfw you will get 80710102 this isnt the psn error for a ban its just failure to obtain your ip you can shut down the ps3 reset your router and then turn it on and run system connection settings>EASY> and it will pick up if not your isp could be to blame as much as anything look into OPEN DNS
here are 2 that should actually help you avoid dns errors its free any isp can use this its from OPEN DNS for this very thing..
208.67.222.222
and
208.67.220.220
anyone feel free to use these as primary and secondary dns to help if your isp is being a azz ache THAT WILL FIX IT

enjoy
Source:
You must login or register to view this content.
Originally posted by another user
I replaced the Roadrunner (or any other ISP's) DNS entries with addresses from the Open DNS project which is a free, secure DNS server that anyone can use. It's safe, easy, and works.
The DNS addresses are:
208.67.222.222 or/and 208.67.220.220
Once replaced, you should have no problem logging in.
BTW, you can also use these DNS servers for your entire network if you like by configuring your router. That however is up to you, and won't be discussed in this particular thread by me since I'm too lazy to make a writeup for every single router out there. However, I do guarantee that this fix will work (or at least get you online with your PS3) for the time being. If it doesn't work, then please re-read this thread and try again before wasting five minutes of your time telling me that it doesn't work.
Also, for those that think that this is a PSN issue; consider this: With TW, I could still browse the net with the PS3. I could also use any of my home PC's without problem. The only time I ever encountered a fault was when trying to log into the PSN network using the TWC supplied DNS addresses. Once I replaced those, the problem went away.
Think about it now. If it was a PSN issue, the OpenDNS addresses woudn't have worked for me or anyone else here either. But, since it did I think it's safe to say that the problem lies with your ISP. Don't forget that alot of ISP's including Time Warner depend on 3rd party DNS hosts. Just because you have TW (or Comcast, or Cablevision, et al), doesn't mean the DNS servers are owned and operated by them as well. Perhaps the DNS provider changed something in their routing tables preventing a connection with PSN. There are ALOT of variables at play here...
That alone could be a reason why others have similar issues with different ISP's. Maybe their ISP uses the same DNS host that Time Warner uses. All you're doing by replacing the DNS address is simply using a different DNS provider; nothing else.