Yep, you'll need to speak to the IT Dept. and get them to sort it out if you think it's that, which is fairly likely. That said, it's odd that it cuts out at that point, usually when firewalls involved it will just block the connection completely. It might be something else network-related though.
Make sure you try other IRC networsk too to make sure it's not a problem with the server, although this is unlikely.
As a note, be aware that if your IT Dept. say they don't want people accessing IRC, or refuse to sort the problem out, we don't help with going against their rules.
Regards,