Many work networks limit connections, especially those used for filesharing.

Really, the best approach would be to first ask the network experts at work if filesharing is allowed.

If they allow filesharing, explain your problem. They may open a port (like the default gnutella port of 6346) that will allow you to connect.

However, they have probably already decided to close as many ports and services as possible in order to provide a more secure network, and may look at a request to open ports as a security threat. So, don't be surprised if they view a port opening request with suspicion.