Firewall Blocks App Store?

We have an extremely limiting firewall here where I work called SonicWall (I think that's the name). It seems to block access to the app store when I try to access it from my iphone. I can get on it just fine if the wifi is off. What is the address or domain that the iphone app store looks up? If I appeal to the gods of our IT department, the might make an exception for this if they know what to unblock.