Fwd: [ns-2] ns subdirectory 403 forbidden access

Hello,
I'm sorry if I'm writing to the wrong mailing-list, but I didn't found a
more appropriate mail address to write to. I'm using ns-2 documentation and
software for my thesis, but it's more than a week that I'm unable to enter
into the ns sub-directory in the website where ns2 files and manual are
hosted ( www.isi.edu/nsnam/ns/ ), since I always get a 403 Forbidden error
(I'm connecting from Italy). I'd like to ask you if there's another website
where I can get these files (Google didn't help me) or if you know an
e-mail address to reach an administrator and signal the problem (if it's
not already known).
Thanks in advance,
kind regards,

Filippo