@s_isale is also correct, if you do not have a data plan (Shary Value Pack) then yes you need user and pass, but your bill should be quite high due to data charges. If you have the data plan then no user or pass needed.
@smoke the fix for your problem has been out for sometime now.
You can also just turn flight mode on for a few seconds and then off again that should do the same thing as rebooting.