I read today the requirements for IBM Connections 4.5 , which will be released on 29th of march. On point there is WebSphere Application Server V8.0.0.5 for Network Deployment.
WebSphere Application Server V8 must be installed through Install Manager, so you have to download 4 packages for the server core and 4 packages for supplements. After this the fixes for 8.0.0.5, what do you think you many data will it be?
You will download more than 10 GB of Software only for WebSphere Installation! 6.x GB for V8 and about 5 GB for fixes.
Here the Software (with some DB2 stuff):