You didn't say which URL you're trying to access, but I'm guessing that only port 80 is open on the firewall. So other ports like 4848 and 8080 are not accessible. If so, you'll have to talk to the network admin about that; my guess is that they will stay closed, though.
Is your server hosted by some ISP?
More importantly is glassfish running?
What does "remotely" mean - are there firewalls in between? How exactly are you trying to access it - which URL are you using?
Can you ping your server remotely?