Depends on their policy, and whether or not the server can actually be seen from the internet. Your best bet is to call their helpline and ask them, although someone on here may have first hand experience of this (which is obviously not me - i'm in the UK! )
If I setup a development server at home, at what point will my isp (comcast) start to get upset about incoming traffic?
I ran game servers for myself and a couple friends (usually about 10 was all my comcast could handle) years ago and never got any complaints. Things might be different now though... do they specifically state that you can't run a home server in your contract?