agreed, I was playing in some games today with lag spikes up to 1200. Now, this is just unacceptable. It makes matters worse when you have to sit through and play 45/60 minute games with lag spikes like this. Frankly, it's not even worth trying to do all the tracing, and pinging and all that other nonsense when the facts are that it is not my ISP and I don't have anything hogging my network either.
I would really suggest that you get your Network Administrator to diagnose this problem, or fire them and get someone that will fix it. Also, it wouldn't hurt for them to at least post something on the forum so I don't waste anymore of my time searching many of these similar posts trying to find answers.