This is actual *.iso image of Red Hat Enterprise Linux 5.1 Server IA64 Binary DVD downloaded from RHN (Red Hat Network).

Since you probably don't have a Subscription Number, you will not be in position to automatically download updates and stuff. You can install it and run it with full "out-of-the-box" functionality - and maybe manually apply updates later (if you know how and where to find them).

I've seen things... You people wouldn't believe...
Penguin